Anterior region of the body that contains the palps, chelicerae and hypostome. Capable of dorsal to ventral flexing motion. Homologous with the gnathosoma of mites. The capitulum articulates with the body via a cavity, the camerostome. The capitulum is located at the anterior end of the body in ixodid ticks and the larvae of many argasid ticks. It is located ventrally or subterminal, obscured by an overhang of the anterior end of the body.
The adult body is the region that includes the prosoma and the opisthosoma.
Ticks have 4 pairs of walking legs as adults and nymphs (only 3 pair occur in larvae). Each leg consists of 6 segments, the coxa, trochanter, femur, patella, tibia and tarsus. The tarsus of each leg bears an apotele comprising the claws and the pulvillus (the latter is absent in most argasid tick nymphs and adults). A complex sensory organ, Haller's organ, is located on the dorsal surface of the tarsus of leg I.
The paired palps are located on either side of the hypostome and the medially-located chelicerae. Each palp consists of four distinct segment (= articles). In ixodid ticks (Family Ixodidae), the fourth palpal segment is reduced and located in a cavity in the terminal end of segment three. In argasid ticks (Family Argasidae), all four palpal segments are similar in length. The palps provide sensory information about the condition of the host skin in preparation for selecting a site for feeding.
Tip-pore setiform sensilla that have dendrites from both mechanosensory and gustatory neurons.
Type A single pore multifunctional sensillum
The third segment of the palp. In ixodid ticks (Family Ixodidae), this segment has a depression on its terminal (distal) end where the fourth palpal segment is inserted.
Fig. 2-9, Fig. 2-10, in Biology of Ticks ISBN:0-19-505910-7.
The fourth and distal most segment of the palp. In ixodid ticks (Family Ixodidae), this segment is much smaller than the other segments and recessed in a depression of article III. The fourth palpal segment contains a prominent field of small tip-pore sensilla that function as gustatory and gustatory/mechanosensory sensilla (possibly also thermosensory functions). These sensilla provide information about the host skin during the attachment phase of tick feeding.
The hypostome is an unpaired, elongated projection from the basis capituli that is inserted into the skin when the tick feeds. The hypostome contains recurved denticles (teeth) on ventral surface and a narrow channel, the food canal (= hypostomal gutter) on itsdorsal surface.
Setiform tip-pore sensilla that have dendrites from gustatory neurons. These sensilla are believed to function as tastereceptors.
Type B single pore chemosensory sensillum
The field of tiny denticles at the anterior end of the hypostome.
The hypostome is armed with numerous recurved denticles (= teeth) that project posteriorly. The denticles are arranged in rows,typically two or three on either side of the center line indicated by the food canal. The number of rows and number of denticles in arow provide useful characters for taxonomic separation of species.
The chelicerae are the cutting organs used by the tick to penetrate the host's skin. Each chelicera consists of a base, a shaftand the cutting digits, both internal and external digits. The chelicerae are covered with a spinose sheath. The chelicerae are retractable.
Food channel through which blood is sucked and/or saliva is delivered.
Fig. 7-5, Fig. 7-12, in Biology of Ticks ISBN:0-19-505910-7.
Spinose sheath covering the cheliceral shafts but not the digits. Fuses with the dorsal covering or tectum.
Delicate inner membrane surrounding the shaft of the chelicera.
Delicate membraneous sheath that can be withdrawn to expose the cheliceral digits.
Fig. 2-5, in Biology of Ticks ISBN:0-19-505910-7.
Bublous area at the junction of the capitulum and the body which contains the muscles that move the cheliceral digits.
Fig. 7-5, Fig. 7-11, in Biology of Ticks ISBN:0-19-505910-7.
Major region of the junction of the capitulum with the body that encloses the cheliceral shafts and cheliceral bases; alsoincludes the pharynx and the salivary ducts.
Roof of the basis capituli that fuses with the outer cheliceral sheaths; also encloses the pharynx, pharyngeal dilater muscles,pharyngeal constrictor muscles and the salivary gland ducts.
Muscles that move the cheliceral digits.
Flexes inner digit in the lateral direction.
Fig. 4-19, in Biology of Ticks ISBN:0-19-505910-7.
Extends (straightens) inner cheliceral digits towards the midline.
adult extensor tendon of cheliceral digit
Large, spiny anterior-most segment of the chelicera that contains cutting spines cutting into the skin of the host.
The large, sharp tooth on the inner digit.
adult medial spine of inner cheliceral digit
The basal segment (=article) of the palp that is attached to the basis capituli.
This sensillum is innervated by a single neuron believed to have a thermosensory function.
Fig. 15-27, in Biology of Ticks ISBN:0-19-505910-7.
Gustatory chemosensory sensillum innervated by 11 chemosensory dendrites.
Fig. 15-27, in Biology of Ticks. ISBN:0-19-505910-7.
Space bounded by the hypostome and chelicerae.
Fig. 7-6, Fig. 7-12, in Biology of Ticks ISBN:0-19-505910-7.
The PSd-1 neuron is believed to function as a thermosensory neuron.
Large flat circular plate at the base of the inner cheliceral digit innervated by mechanosensory dendrites. The placoid sensillum is a mechanosensillum.
Fig. 15-29, in Biology of Ticks ISBN:0-19-505910-7.
Nerve within cheliceral digits supply mechanosensory and chemosensory (gustatory) neurons.
Branch from cheliceral nerve containing mechanosensory dendrites.
Branch comprising cluster of 11 chemosensory dendrites from cheliceral nerve to PS-2 pit sensillum.
Nerve comprising mechanosensory, chemosensory (mostly gustatory) neurons to palpal sensory field sensilla at the tip of Article IV.
Fig. 14-1, in Biology of Ticks ISBN:0-19-505910-7.
Paired depressions on dorsal surface of the basis capituli of females containing numerous tiny pores. Function obscure. Believed to supply antioxidants preventing degradation of unsaturated lipids that comprise the waxy secretions supplied by Gene's organ. If the porose areas are blocked, Gene's organ does not function properly.
Fig. 4-1, Fig. 7-4, in Biology of Ticks ISBN:0-19-505910-7.
Dorsal plate found in all stages of all ixodid ticks; absent in Argasidae. Sclerotized plate for muscle attachment. Covers anterior region of the body in larvae, nymphs and the entire dorsal body surface in males.
Flap like structure covering the roof of the preoral canal. Very short in ixodid ticks but long in argasid ticks and extending over the full length of the preoral canal (hypstomal gutter). In argasid ticks, the labrum can move up and down, thereby separating the blood flowing into the mouth from the saliva expelled above it into the salivarium. In argasid ticks, the labrum is hollow and filled with fluid. This is an adaptation for rapid feeding characteristic of these ticks.
Opening found at the junction of the preoral canal and the anterior pharygneal valve (opening of the pharynx).
Plate for attachment of dorsal dilator muscle of the pharynx.
Fig. 7-12, in Biology of Ticks ISBN:0-19-505910-7.
Powerful sucking organ that serves as a sucking pump to suck blood from the host during blood feeding. Surrounded by powerful constrictor and dilator muscles.
A system of tracheal trunks and anastomosing tracheae that extend throughout the body, capitulum and legs to supply oxygen tothe cells and tissues and remove waste CO2. The tracheae end in tracheoles within the individual tissues. Opens to the exterior via the paired spiracles on the lateral margins of the body.
The large chamber just below the ostium that connects the subostial space with the tracheal trunks.
Cavity into which blood flows. Separated from the mouth by the anterior pharyngeal valve and the esophagus by the posterior pharyngeal valve. Tri-radial shaped cavity when collapsed, subcircular when filled with fluid.
Bands of striated muscles that surround the pharynx and collapse it, driving blood posteriorly. Constrictor muscles alternate with dilator muscles to effect the characteristic pumping action.
Bands of striated muscles extending from the ventral internal surface of the basis capituli to the ventral surface of the pharynx. Alternating with constrictor muscles.
Bands of striated muscles extending from the epistome (subcheliceral plate) of the basis capituli to the dorsal surface of the pharynx. Alternating with constrictor muscles.
Bands of constrictor muscles extending from the lateral margins of the basis capituli to the pharynx.
Fig. 7-10, in Biology of Ticks ISBN:0-19-505910-7.
Valve at the anterior end of the pharynx and mouth opening at the end of the preoral canal.
Fig. 7-5, Fig. 7-9, in Biology of Ticks ISBN:0-19-505910-7.
V-shaped moveable sructure (wedge) that contributes to opening and closing of the valve by fitting into the mouth at the end of the pre-oral canal, thereby opening or closing the connection to the pharynx. When the wedge is raised, the valve is opened, allowing fluid uptake. When lowered, the valve is closed by collapse of its walls and regurgitation is blocked. Opening and closing of the valve is coordinated with constriction and dilation of the pharynx to propel blood posteriorly and prevent regurgitation.
Wing-shaped sclerotized plates for support of muscles controlling the action of the pharyngeal valve, Muscle bundles extendfrom the alae to the subcheliceral plate (epistome) and from the alar surfaces to the ventral side of the basis capituli. Dilator muscles of the pharynx also attach to the alar plates. Operation of the anterior pharyngeal valve is accomplished by the contractionof the dilator muscles inserted on the wing-like alae, thereby raising or lowering the v-shaped wedge. When the wedge is raised,fluid is taken up, when lowered, it projects down into the v-shaped valve, sealing it and prevents backflow.
Muscles within the hypostome that extend from the lateral margins to the pre-oral canal (hypostomal gutter) and dilate the channel. Most prominent in argasid ticks.
Ducts from the salivary glands to the salivarium. The salivary duct is easily recognized by its banded structure, resembling the taenidia of the trachea, and its connection to the salivary gland. The type I agranular acini are connected directly to the main salivary duct. Intralobular ducts connect at various locations to the main duct, transporting the secretions of the granular acini into the main duct.
Fig. 7-5, Fig. 7-10, in Biology of Ticks ISBN:0-19-505910-7.
A nerve that originates in the stomadeal pons of the synganglion and runs alongside the esophagus to a hypoesophageal ganglion adjacent to the retrocerebral organ complex (ROC).
Fig. 14-16, in Biology of Ticks ISBN:0-19-505910-7.
Small teeth on the inner walls of the pharyngeal valve in some ixodid ticks; absent in argasid ticks. When apposed by themoveable v-shaped wedge, the teeth and wedge form a sort of grinding organ.
Cuticle-lined duct from the end of the pharynx to the midgut. No valve has been found at the exit of the pharynx into theesophagus.
Remainder of the dorsal body surface posterior to the scutum. Covered with flexible, grooved cuticle and capable of extensive expansion.
Fig. 4-1, in Biology of Ticks ISBN:0-19-505910-7.
Aperture on the ventro-lateral margin of the body. Paired structure located on opposite sides of the body at the same location. In ixodid ticks, the spiracle is located posterior to leg IV and embedded in a large spiracular plate. In argasid ticks, the spiracleis located between legs III and IV, adjacent to a small spiracular plate.
Plate surrounding or adjacent to spiracle on the ventro-lateral margin of the body. Large plate covered with numerous pore-likestructures in ixodid ticks, small pore-like structures in argasid ticks. Located posterior to leg IV in ixodid ticks, posterior toleg III in argasid ticks.
Simple eye located on dorso-lateral margin of dorsum, adjacent to the scutum. Paired structure, one on each side of the body. In some species, the eye is located on the lateral margin of the scutum.
Fig. 15-30, in Biology of Ticks ISBN:0-19-505910-7.
Simple eye located on the ventro-lateral margin of the body between legs III and IV. Paired structure, one on each side of thebody. Not universally present; some species are without eyes.
Paired structure on dorsal body. In females, the foveal pores are located in the alloscutal region just posterior to the scutum. In males, the much smaller foveal pores are located in the middle of the sctum. The foveal pores contain numerous tinyapertures and serve as the site for emission of the sex pheromone, 2,6-dichlorophenol. Absent in Prostriate and argasid ticks.
Paired multicellular glands connected to the foveal pores by simple ducts. Each gland consists of large cells filled withinnumerable lipid droplets containing sex pheromone, 2,6-dichlorophenol. Site of sex pheromone biosynthesis and secretion during female feeding.
Single sensory nerve innervating the foveal glands.
Pore located in the ventral midline of the body for elimination of fecal and excretory wastes.
Located in anterior ventral midline between the coxae of legs II and III. Location where spermatophores are inserted duringcopulation and from which ova emerge during oviposition. Subtriangular depression in ixodid females; broad, lateral slit in argasidfemales. Opens into the vestibular vagina.
Located in anterior ventral midline between the coxae of legs II and III. Subrectangular structure. Location from which thespermatophores are extruded from the male body during copulation. Covered by a movable flap which opens to allow the spermatophore to emerge.
Fig. 2-3, Fig. 4-8, in Biology of Ticks ISBN:0-19-505910-7.
Groove in the ventral posterior mid-line of the body anterior to the anal pore in the Prostriata but posterior to the anal pore in the Metastriata.
Groove that separates the dorsal and ventral regions of the body along the lateral margins. Found only in argasid ticks of thegenus Argas. A margin groove also occurs on the dorsal body surface of females of the genus Ixodes.
Fig. 2-2, in Biology of Ticks ISBN:0-19-505910-7.
Protruding anterior extension of the body in argasid ticks of the genus Ornithodoros that obscures the capitulum in dorsal view.
Fig. 2-6, Fig. 7-2, in Biology of Ticks ISBN:0-19-505910-7.
Region of the body posterior to the leg coxae that bears the spiracles and the anal aperture.
Region of the body bearing the legs and the genital pore.
Sclerotized plate on the ventral surface of the males of the genus Ixodes anterior to the genital pore.
Fig. 2-3, Fig. 4-2, in Biology of Ticks ISBN:0-19-505910-7.
Slerotized plate on the ventral median region of the body of males of the genus Ixodes. Located posterior to the male genitalpore but anterior to the anal pore.
Sclerotized plate on the body of the males of the genus Ixodes located posterior to the median plate and surrounding the anal pore.
Fig. 4-2, in Biology of Ticks ISBN:0-19-505910-7.
Sclerotized plate on ventral opisthosomal surface of the males of the genus Ixodes lateral to the anal plate.
Sclerotized plate on the ventral opisthosomal region of the males of the genus Ixodes. Located along the lateral margin of the body posterior to the spiracular plate.
Paired flap like structures on the anterior ventral surface of the body adjacent to the capitulum of argasid ticks of the genus Ornithodoros.
Paired glands located in the ventral anterior region inside the body of adult and nymphal argasid ticks.
Collecting tubule of each coxal gland. Consists of several regions ending distally in the coxal pore.
Tiny pore located on each side of the ventral opithosomal region of the body of argasid ticks between the coxae of legs I andII. Absent in ixodid ticks.
Region of the coiled collecting duct within the body of the coxal gland. Connects to the coxal pore.
Fig. 10-10, in Biology of Ticks ISBN:0-19-505910-7.
Region of the coiled collecting duct of the coxal gland. Located entirely within the body of the coxal gland and surrounded bythe filtration membrane. Responsible for water and salt elimination and selective ion resorption.
Highly folded delicate membrane forming the outer surface of the coxal gland of argasid ticks. Invests the interior coiledcollecting ducts in a labyrinthine network. Responsible for ultrafiltration of walter and salts from the hemolymph.
Fig. 10-9, in Biology of Ticks ISBN:0-19-505910-7.
Cells that form the lining of the coiled collecting duct of the coxal glands.
Fig. 10-11, in Biology of Ticks ISBN:0-19-505910-7.
Ducts of the foveal glands connecting the secretory cells of the foveal glands with the foveal pores in the foveae on the body surface.
Numerous tiny slit-like pores that occur on the surface of the allocscutum in ixodid ticks. Also occur on the surface of thescutum. These pores function as mechanosensilla.
Fig. 4-4, in Biology of Ticks ISBN:0-19-505910-7.
Hair-like structures that occur all over the body. Most are mechanosensory in function.
Paired grooves located in the median region of the scutum in most ixodid ticks.
Fig. 2-2, Fig. 4-1, in Biology of Ticks ISBN:0-19-505910-7.
Paired shallow grooves that occur near the lateral regions of the scutum in some prostriate ixodid ticks.
Ridges located on the lateral sides of the scutum in some ixodid ticks.
Cavity with elevated margins in the anterior region of the body within which the capitulum is situated.
Fig. 2-6, in Biology of Ticks ISBN:0-19-505910-7.
Innumerable tiny folds of cuticle on the surface of the body of argasid ticks of the genus Ornithodoros. Presents a granularappearance. Absent in larvae. Absent in ixodid ticks.
Fig. 2-4, Fig. 2-20, in Biology of Ticks ISBN:0-19-505910-7.
Small rectangular plates that occur on the surface of the body of argasid ticks of the genus Argas.
Groove located in the ventral median opisthosomal region of the body of some argasid ticks, especially species of the genus Ornithodoros. Extends from the anus to the transverse post-anal groove. Absent in larvae.
Fig. 4-12, in Biology of Ticks ISBN:0-19-505910-7.
Groove located near the posterior margin of the ventral opisthosomal region of some species of argasid ticks, especially in the genus Ornithodoros. Intersects with the post-anal groove. Absent in larvae.
Numerous semi-transparent structures throughout the surface of the spiracular plate containing aeropyles within each goblet. Absent in argasid ticks.
Fig. 12-1, in Biology of Ticks ISBN:0-19-505910-7.
Cavities within the spiracular plate structure represented externally by the goblets. Separated from one another by pedicels.
Pillars of cuticle separating the individual air spaces (aeropyles).
Fig. 12-4, in Biology of Ticks ISBN:0-19-505910-7.
Small raised structure adjacent to the ostium.
Opening from the atrial chamber of the respiratory system to the exterior. In argasid ticks, pressure from the raised macula closes the ostial aperture.
Prominent anteriorly protruding spine-like extension of the scutum on either side of the capitulum in some species of ixodid ticks.
Fold along the dorso-lateral margin of the body in some species of ixodid ticks, separated on the medial side by the marginalgroove.
Prominent folds on the ventro-lateral margins of argasid ticks adjacent to the leg coxae. The eyes, spiracles and coxal poresare located on the supracoxal folds.
Fig. 2-5, in Biology of Ticks ISBN:0-19-505910-7, Fig. 25.
Subrectangular areas on the ventral posterior margins of the body of some species of ixodid ticks.
Prominent fold on the ventral surface of the body in some argasid ticks adjacent to the leg coxae.
The body covering consisting of the cuticle and the underlying epidermis.
Fig. 5-1, Fig. 5-2, in Biology of Ticks ISBN:0-19-505910-7.
Tissue that secretes the cuticle. Layer of epithelial cells. Also secretes enzymes that dissolve old cuticle and secrete newcuticle during molting.
Dead outer part of the integument made up of primarily of protein and chitin.
Thin (1 - 2 microns) outermost layer of the cuticle composed entirely of protein. This layer is not resorbed during molting butis shed during the molting process and discarded (exuviae or molted skin).
Region of the cuticle under the epicuticle composed of a mixture of protein and chitin compounds. Resorbed during the ecdysial(molting) process.
Fig. 5-1; Fig, 5-2, in Biology of Ticks ISBN:0-19-505910-7.
Consists of numerous microfibrils perpendicular to the cuticular surface forming a striated appearance (as seen with theelectron microscope).
Thin electron dense layer composed of complex tanned lipoproteins. First layer secreted during cuticle synthesis.
In ixodid ticks, this is the outermost layer. Secreted by the dermal glands.
Outermost layer of the epicuticle in argasid ticks. Secreted by the dermal glands. Present only in argasid ticks.
Glands located in the integument consisting of two or three cells that secrete waxy fluids onto the cuticle via ducts. Most common type of dermal gland. In Argasidae, these glands are believed to secrete the cement layer.
Dermal glands located on the ventro-lateral regionof the body of the males of several African Amblyomma species. The glands comprise two or three enormously enlarged cells. These glands are reported to be the site of biosynthesis and secretion of the bont tick attraction/aggregation/attachment (AAA) pheromone. See also J. Chem. Ecology 17: 833 - 847.
Paired glands comprised of clusters of white multicellular acini (lobes) arranged around a common salivary duct. The salivary glands are located in the antero-lateral regions of the body. The salivary glands are among the largest glands in the body. The salivary glands are comprised of two types of acini (alveoli), agranular acini (type I acaini) located near the anterior end of the gland and up to three types of granular acini (types II, III and IV), located in the middle and posterior regions of the gland. Agranular acini open directly into the main salivary duct. The granular acini open into intralobular ducts that ramify among the acini, eventually joining the main salivary duct.
Outermost, non-lamellated region of the procuticle.
The innermost zone of the procuticle. This region contains numerous lamellae composed of tiny microfibrils. It is permeated by innumerable tiny canaliculi that pass through the endocuticle, forming an anastomosing network of canals.
Tiny submicroscopic or barely microscopic canaliculi normally visible only with the electron microscope. Permeate the endocuticle. Function unknown.
Duct from the cells of the dermal gland to the exterior of the cuticle.
Valve-like structure at the junction of the dermal gland duct and the dermal gland cells.
Socket-like sensilla, somewhat broader than the sensilla auriformia, that occur on the surface of the alloscutum. Believed to function as strectch receptors.
Cluster of non-granular cells located along the anterior part of the salivary ducts. Also known as agranular acini. Believed to be responsible for hygroscopic regulation of water balance by direct sorption of atmospheric moisture. Type I acini secrete highlyconcentrated salty solutions into the preoral canal and suck back the dilute solutions, thereby gaining new water.
Granular acini clustered around secondary salivay ducts. Do not connect directly to the main salivary duct, but rather connectvia secondary ducts. Type II acini contain three types of granular cells, A, B and C, so-called because of differences in the granules.
A cluster of acini located primarily in the posterior region of the salivary gland, connected via secondary ducts to the mainsalivary gland duct. Comprised of three major cell types, D, E and F cells. According to Jaworski et al (1992), the cement compoundsused to bind the tick mouthparts to the host skin are elaborated in the D and E cells of these acini. Bishop et al (2002) report acement protein from the type E cells of the type III acini in Rhipicephalus appendiculatus. The F cell is transformed during bloodfeeding by membrane infolding to form an enormous labyrinthe system for extracting water and salts from the hemolymph and secreting them into the salivary ducts for excretion back into the host. The type III acini are the primary sites for development of sporozoites of Theileria parva, the agent of East Coast Fever.
Fig. 8-10, in Biology of Ticks ISBN:0-19-505910-7.
Type of cell found in the Type II acini of the salivary glands in ixodid ticks. Type A cells contain numerous granules ofunknown function.
Cells found in the Type II acini. Crause et al (1993) reported finding that tick toxin from three species of ixodid ticks wasidentified in these cells by immunocytochemical assay.
Cell type found in the Type II acini of the salivay glands of ixodid ticks.
Large cell in the center of the acini in direct contact with the main salivary duct. The membrane is folded into a labyrinthine network with the lamellae oriented from the apex to the periphery of the cells. This profusion of densely packed lamellae almost all oriented in the same direction gives the acinus its characteristic foliate or striate appearance when viewed with the light microscope.
Fig. 8-5, in Biology of Ticks ISBN:0-19-505910-7.
adult salivary gland type I central cell
Large cells located along the peripheral margins of the type I acini. The cytoplasm of the peripheral cells also exhibits anenormous proliferation of lamellate sheets at their hemolymph borders contributing their striate appearance when viewed with the light microscope.
adult salivary gland type I peripheral cell
Cells reponsible for secreting the intralobular acinar duct. In type I acini, the acinar duct is extremely short and leads directly into the main salivary duct. Thus the agranular type I acini appear to communicate directly with the main salivary duct. In the type II and type III acini, the acinar duct is bifurcated and communicates with the secondary ducts, not the main salivary duct.
Bifurcate ducts from within the acini that coalesce and fuse with the main salivary duct. Salivary fluids from the acini are transported via these secondary ducts to the main salivary duct for transport to the exterior.
These cells occur along the outer edges of the type II or type III acini, sandwiched between the much larger granule-filled secretory cells.
adult salivary gland granular acini ablumenal cell
Long narrow cells that are situated between the much larger granular secretory cells and extend from the central lumen almost to the periphery of the acinus. During feeding, the adlumenal cells enlarge and function as myoepithelial cells.
adult salivary gland granular acini adlumenal interstitial cell
A type of granular acinus found only in males of ixodid ticks.
Cell type found in the type III acini of the salivary gland. Each D cell occurs near the acinar duct and resembles the A cells of the type II acini. The D cells contains heterogenous, compound granules composed of numerous subunits. The D and E cells are believed to secrete the compound or compounds that are a part of the attachment cement ( A 90 kDa protein homologous in part with a smaller protein found in the cement cone).
Cell type found in the Type III acini of the salivary glands. This is the dominant cell type found in the Type III acini. These cells are filled with numerous homogeneous granules up to 6 microns in diameter. These granules are composed of numerous densely packed subunits. E cells are also (along with D cells) believed to the site of biosynthesis and secretion of the cement compounds. These cells deplete the granules soon after attachment and gradually atrophy as feeding progresses.
Cell found in the type III acini of the salivary gland. These cells deplete their granules within two days after attachment. Thereafter, they transform, develop an elaborate basal labyrinth and a huge intra-acinar lumen. They complete their transformation and their fullest development during the period of rapid engorgement. They are now specialized for rapid water and electrolyte secretion which enables the tick to suck huge quantities of blood while eliminating the excess blood meal water.
Undifferentiated cells (stem cells) from which all other cell types differentiate during and after feeding.
Secretory cells filled with spherical secretion granuls. The secretions of the Type IV acini are believed to contribute somecomponent of the saliva that reduces spermatophore adhesion during copulation so t hat the spermatophore can be transferred to the female genital pore without adhering to other body structures.
Small, secondary ducts that connect the individual granular acini to the main salivary duct.
Temporary lumen that forms in the Type III acinus during the later stages of blood feeding when the F cells transforms and prepares the acinus for water elimination.
System consisting of the heart, aorta, periganglionic sinus, pericardial sinus, dorsal and ventral anterior sinuses and the four pedal arteries.
An elongated thin walled, saclike structure composed of a layer of epithelium and smooth muscle fibers located in the dorsal mid line of the body lying just below the paired dorsal foveae.
Fig. 11-1, in Biology of Ticks ISBN:0-19-505910-7.
A thin membranous epithelial sac that surrounds heart and separates it from the hemocoel. The pericardial sinus filters the hemolymph that diffuses into the pericardial sinus before entering the heart.
Narrow hemolymph-filled cavity surrounding the synganglion and continuous with the pericardial sinus.
Bulbous thickened posterior region of the heart. This is the pulsatile region. The heart muscle is especially thickened here with bands of striated muscle oriented circularly. Constriction of the muscles in this region drives the hemolymph anteriorly.
Cone shaped anterior region that fuses with the aorta. In the anterior region, the heart is cone-shaped with the muscles oriented longitudinally. An aortic valve located at the junction between the end of the anterior region and the aorta prevents backflow.
Two pairs of ostia occur, two on either side, in the bulbous posterior region. The ostia are surrounded by muscle bandsfascilitating their closure. This prevent backflow when the heart muscles constract.
Valve located between the junction of the anterior region of the heart and the aorta. This valve opens when the heart muscles contract, but prevents backflow when the heart relaxes.
Short, muscular tube that connects the heart with the periganglionic sinus.
Muscle bands that contribute to dilation of the heart.
adult dorsolateral suspensory muscles of the heart
Muscles that contribute to the dilation of the heart.
adult ventrolateral suspensory muscles of the heart
"Blood vessel" that extends from the periganglionic sinus towards the anterior end of the body.
Vessel from the periganglionic sinus that surrounds the first pedal nerve trunk.
Vessel from the periganglionic sinus that surrounds the second pedal nerve trunk.
Vessel from the periganglionic sinus that surrounds the third pedal nerve trunk.
Vessel from the periganglionic sinus that surrounds the fourth pedal nerve trunk.
In ixodid ticks, this system includes the malpighian tubules, the intestine, the rectal sac, and the anus. In argasid ticks, italso includes the coxal glands.
A pair of thin-walled extremely long, coiled and folded tubules that extend throughout the body. The wall of the malpighiantubules consists of cuboidal or sub-cuboidal epithelial cells. Each malpighian tubule connects to the rectal sac on its lateralmargins. Responsible for extraction and elimination of nitrogenous waste. Normally, the malpighian tubules are filled withsubspherical guanine crystals which are produced in this location.
Region of the alimentary system concerned with waste accumulation and water resorption. The hindgut is comprised of the intestine, the rectal sac and the rectum (rectal canal or anal canal).
Short thin tube connecting the midgut with the rectal sac. Absent in some species of argasid ticks.
Fig. 10-1;in Biology of Ticks ISBN:0-19-505910-7.
Large thin-walled organ located in the posterior region of the body. Connected to the midgut by the intestine and to theexterior of the body by the anus. A pair of malpighian tubules connect to the rectal sac on either side. The rectal sac is filled with guanine crystals and fills with hematin and other wastes from the midgut during blood feeding. The hindgut is believed to be responsible for some water and selective salt resorption and may also be responsible for excreting nitrogenous wastes. The rectal sacis a simple sac in ixodid ticks, but bifurcated in argasid ticks.
Short cuticle-lined tube connecting the rectal sac to the anus (anal pore). The rectal wall consists of a thin layer ofepithelial cells on a delicate basement membrane.
Fig. 10-3, in Biology of Ticks ISBN:0-19-505910-7.
A thin layer of cuboidal cells covered with innumerable microvilli on their lumenal surfaces that forms the inner lining of the malpighian tubules.
adult malpighian tubule epithelial lining
A thin layer of squamous epithelial cells and smooth muscle cells that form the outer wall of the malpighian tubules.
Fig. 10-7, in Biology of Ticks ISBN:0-19-505910-7.
System comprising the foregut, midgut and hindgut. System for ingesting host blood, digesting it and eliminating wastes fromblood feeding.
Region of the alimentary canal where digestion of the blood meal takes place. The midgut is the largest organ in the body ofthe tick.
Cenral part of the midgut from which various diverticula emerge and spread in all three planes throughout the body. At the anterior end of the stomach is the proventriculus. The posterior end of the stomach is connected to the intestine through which wastes pass to the rectal sac.
Paired midgut diverticula that extend from the anterior diverticulum and proceed anteriorly into the median region of the bodytowards the capitulum.
Fig. 6-3, Fig. 9-2, in Biology of Ticks ISBN:0-19-505910-7.
Paired midgut diverticula that extend from antero-median diverticula anterolaterally into the lateral regions of the body.
Paired midgut diverticula that extend from the stomach (ventriculus) anteriorly and subdivide into the anterior median and theanterior lateral diverticula.
Fig. 9-2, in Biology of Ticks ISBN:0-19-505910-7.
Paired midgut diverticula that extend from the stomach (ventriculus) to the lateral regions of the body.
Paired diverticula that extend from the stomach (ventriculus) to the postero-lateral margins of the body.
adult midgut postero-lateral diverticulum
Paired diverticula that emerge from the postero-median region of the stomach (ventriculus) and extend into the mid-posteriorregions of the body.
Valve located at the junction of the esophagus and the antero-ventral region of the stomach portion of the midgut. The proventriculus is surrounded by several layers of smooth muscle fibers. The proventriculus opens when the pharynx contracts, allowing ingested blood to enter the midgut, but closes when the pharynx dilates. The latter is believed to prevent regurgitation of blood from the midgut back into the host. However, this remains a controversial issue since some authors (e.g., Burgdorfer et al. 1989) have argued that regurgitation can occur while others (Riberio et al. 1987) consider it unlikely. Connat (1991, Parasitol. Res. 77: 452 -454) showed compelling evidence of regurgitation using tritiated ecdysteroids). Thus, it appears that there is good evidence that it can occur in argasid ticks. Whether it can also occur in ixodid ticks is uncertain.
Fig. 14-17, in Biology of Ticks ISBN:0-19-505910-7.
Layer of epithelial cells comprising multiple cell types that carry out the secretory, absorptive and digestive functions of the midgut.
The outer layer of the midgut comprising a single layer of elongated smooth muscle cells that form the outer wall of this organ.
Early stage digestive cell concerned with hemoglobin digestion. DGC I cells enlarge greatly during the early growth phase offeeding prior to mating. They fill with numerous inclusion bodies (phagolysosomes) containing hemoglobin in varying phases ofdigestion, but little hematin.
Midgut digestive cell in advanced stage of hemoglobin digestion. DGC II cells enlarge greatly and fill with masses of blackhematin residues which accumulate near the distal, luminal sides of the cells. Eventually, these cells rupture and their remnantsfloat freely in the midgut lumen.
Differential epithelial cell that enlarge greatly during feeding and become flask shaped in appearance and fill with largenumbes of granule-filled vesicles. Secretion is accomplished by expulsion of the secretory granules (exocytosis). Coons et al (1986)dispute the existence of secretory cells and claim that they are merely different phases of digestive cell activity.
The internal cavity within the midgut where ingested blood is contained and wastes from blood meal digestion accumulate.
Region of the alimentary system comprising the preoral canal (hypostomal groove or gutter), mouth, pharynx, esophagus andproventriculus.
This system consists of the synganglion, the peripheral nerves and the neuroendocrine systems consisting of 1) clusters ofneurosecretory cells located in specialized neurosecretory centers in the synganglion proper and 2) neurohaemal organs or tissuesadjacent to the synganglion.
The synganglion constitutes the entire central nervous of the tick. There is no separate brain or ventral nerve chord. The synganglion is located in the midventral region of the body immediately posterior to the genital pore in adults or the location where the genital pore will form in immature specimens. The synganglion is a small white organ approximately 0.5 mm wide by 0.4 - .05 mm long. The esophagus penetrates through the synganglion, entering more or less from the anterior ventral side and emerging near theposterior dorsal side of the organ.
Region of the synganglion lying anterior and dorsal to the esophagus. It is the smaller of the two major regions of the synganglion. It contains protocerebrumm cheliceral, palpal, optic ganglia and the stomadeal pons. An unpaired pharyngeal nerve andthe recurrent nerve also originate here and innervate the pharynx and the esophagus, respectively. The recurrent nerve runs alongside the esophagus to a hypoesophageal ganglion adjacent to the retrocerebral organ (ROC).
adult synganglion supraessophageal region
Region of the synganglion located ventral and posterior to the esophagus, hence the name. It is the largest part of the synganglion. It contains the 4 pairs of pedal ganglia, the olfactory ganglia and the opisthosomal (= ventral) ganglia.
Thin layer of squamous epithelial cells that form the outer wall of the periganglionic sinus.
The neurilemma forms the outermost part of the synganglion. It consists of a layer of fibrous material organized in repititivelayers of fine lamellae and finely granular material in a sheath 2 - 5 microns thick.
This structure lies immediately below the perineurium. It consists of a complex multiple layer of gmostly lial cells and their processes.
Outer region of the synganglion containing the neuron cell bodies and the various neurosecretory centers.
Innermost region of the synganglion containing the fiber tracts made up of numerous axons and dendrites.
Type I neurons have perikarya that usually range in size from 6 - 9 microns (rarely, 27 - 35 microns). They have a pyriform shape narrowing at end one to funicle from which the axon and the dendrite diverge. They have a low cytoplasmic: nuclear ratio. Type I neurons are believed to function as motor neurons or motor-association neurons.
Fig. 14-11, in Biology of Ticks ISBN:0-19-505910-7.
adult synganglion cortical zone neuron type I
Type II neurons are neurosecretory (NS) cells, 25 - 40 microns in size and filled with masses of neurosecretory vesicles. They have much larger cytoplasmic: nuclear ratio than the type I cells. Type II cells are located in neurosecretory centers.
adult synganglion cortical zone neuron type II
Type III neurons are small (6 microns) cells that represent a unique cell type limited tothe paired globuli on the ventralsurface of the synganglion anterior to the first pair of pedal ganglia.
adult synganglion cortical zone neuron type III
A large area of loosely organized neuropile that also contain glomeruli.
Small areas of high density neuropile located within the protocerebrum.
Transversely directed fiber tracts connecting bilaterally opposed glomeruli or ganglia.
Longitudinally-directed fiber tracts connecting glomeruli or ganglia arranged in the antero-posterior axis with glomeruli or glomerular knots throughout the synganglion.
Masses of neuron cell bodies from which the cheliceral nerves emerge. Located in the antero-dorsal region of the supra-esophageal region.
Masses of neuron cell bodies from which the palpal nerves emerge. Located in the antero-dorsal region of the supra-esophagealregion.
The space located immediately below the ostium of the spiracle and connected to the atrial chamber.
Site of origin of the unpaired pharyngeal nerve (=esophageal nerve) and the recurrent nerve (=stomatogastric nerve) to thehypoesophageal ganglion.
Located adjacent to the retrocerebral organ complex (ROC). Receives the recurrent nerve from the stomadeal pons.
adult synganglion hyperesophageal ganglion
The ROC is situated in the periganglionic sinus adjacent to the protocerebral neuropilar ganglion. In view of its location, theROC is believed to function as a neurohemal organ. Some authors believe that the ROC is not of neural origin (Severino et al. 1984).
adult synganglion retrocerebral organ complex
The unpaired lobe is located in the dorsal median part of the organ complex.
The pair of lobes located on the ventral side of the ROC.
Center where axons from sensory neurons converge.
adult synganglion anterodoral glomerulus
Site where axons from certain sensory neurons converge. Dendrites extend from the glomeruli to other locations.
adult synganglion posterodorsal glomerulus
Ganglion from which the fibers that form the pedal nerve trunk I emerge.
Ganglion from which the fibers that form the pedal nerve trunk II emerge.
Ganglion from which the fibers that form the pedal nerve trunk IIII emerge.
Ganglion from which the fibers that form the pedal nerve trunk IV emerge.
Lobes containing the olfactory neuron cell bodies (=olfactory ganglia). Located medially to the pedal ganglia. Believed to receive the axons from the Haller's organ olfactoreceptors.
Centers where axons from neurons associated with the olfactory lobes converge. Located internally and medial to the olfactory lobes.
Fig. 14-3, in Biology of Ticks ISBN:0-19-505910-7.
Center where axons from the opisthosomal (= ventral) ganglion converge.
Fused ganglion containing the neuron cell bodies from which the paired opisthosomal and paraspiracular nerves originate. Located posterior and medial to the pedal ganglia. Believed to receive the axons from the Haller's organ olfactoreceptors.
System comprising the nerves that innervate the various body, capitulum and leg structures.
The peripheral nerves are comprised almost exclusively of axons surrounded by glial cells and enclosed in an amorphous neurilemma. The neurilemma fuses with the glial cells to form a sheath around the individual axons or groups of axons termed the mesaxon. Mesaxons are a characteristic feature of tick peripheral nerves. Mesaxons do not occur in insects.
A sheath that surrounds the individual axon or group of axons in a peripheral nerve. The mesaxon is formed by the fusion of the neurilemma withthe glial cells.
Fig. 14-22, in Biology of Ticks ISBN:0-19-505910-7.
Non-neuronal cells that provide support and nourish the neurons and possibly help maintain homeostasis.
Fig. 14-20, in Biology of Ticks ISBN:0-19-505910-7.
Large nerve that emerges from pedal ganglion I. The major branch of this nerve innervates the muscles of leg I. Minor branchestermed hemal nerves innervate the salivary glands, the periganglionic sheath, coxal muscles and possibly the dermal glands.
Large nerve that emerges from pedal ganglion II. The major branch of this nerve innervates the muscles of leg Ii. Minor branches termed hemal nerves innervate the salivary glands, the periganglionic sheath, coxal muscles and possibly the dermal glands.
Large nerve that emerges from pedal ganglion Iii. The major branch of this nerve innervates the muscles of leg IV. Minor branches termed hemal nerves innervate the salivary glands, the periganglionic sheath, coxal muscles and possibly the dermal glands.
Large nerve that emerges from pedal ganglion IV. The major branch of this nerve innervates the muscles of leg IV. Minor branches termed hemal nerves innervate the salivary glands, the periganglionic sheath, coxal muscles and possibly the dermal glands.
Nerve that emerges from the cheliceral ganglion and innervates the cheliceral muscles and chelicerae. Contains motor axons fromthe synganglion and presumably axons from the sensilla.
Nerve that emerges from the palpal ganglion and innervates the palps, including the sensory field at the tip of palpal articleIV. Contains motor axons from the synganglion and presumably axons from the sensilla.
Nerve that extends from the stomadeal pons to the pharynx and esophagus.
A pair of nerves that emerge from the optic ganglia and innervate the eyes. Contains axons from the sensory neurons in the eyes.
A neuronal cell type concerned with sensory perception.
Large cuticle lined tubes that extend from the atrial chambers and then subdivide into numerous individual tracheae.
Fig. 12-5, in Biology of Ticks ISBN:0-19-505910-7.
A pair of nerves that extend from the opisthosomal ganglia on the ventral surface of the synganglion to various organs and tissues in the posterior region of the body.
Collection of neurohaemal organs adjacent to the synganglion and neurosecretory centers in the synganglion. The neuroendocrinesystem is responsible for secretion of bioactive molecules that regulate physiological processes in the tick.
The retrocerebral oran complex is a major neurohaemal organ located in a neurohaemal sinus that connects with the periganglionic sinus around the synganglion. The ROC is located immediately above the posterior dorsal region of the supraesophageal region of the synganglion. The ROC consists of an unpaired dorsal lobe and paired ventral lobes. Regarded as an important neurohaemal organ but its precise role remains uncertain.
Cells found in the hemolymph. Four cell types have been recognized in ticks, prohemocytes, plasmatocytes and two types ofgranulocytes, type I and type II and spherulocytes. In some literature, a type known as the oenocytoid is also described but itsstatus is somewhat controversial.
Prohemocytes are the stem cells from which all other hemocytes develop. They are small, round or oval cells with very little cytoplasm surrounding the nucleus. Prohemocytes constitute a very small proportion of the hemocyte population.
Fig. 11-3, in Biology of Ticks ISBN:0-19-505910-7.
Plasmatocytes are relatively small oval, suboval or fusiform cells but without granules. The plasma membrane shows blunt or filamentous projections. They often show prominent inclusion bodies and vacuoles indicative of substances that have been ingested. Plasmatocytes are believed to function as phagocytes and play a major role in phagocytosis.
Type I granulocytes are hemocytes with numerous diverse inclusion bodies of varying density, some that are very electron denseand believed rich in lipids, others that are electron lucent and contain a matrix of fibrillar material.
Fig. 11-6, in Biology of Ticks ISBN:0-19-505910-7.
Type II granulocytes are hemocytes that are easily recognized by the presence of a single type of electron dense, homogenous granules. In addition to their role in phagocytosis, these cells also serve to encapsulate foreign material too large to be ingested. They are believed to be the primary cell that degranulates and forms around bacterial cell clusters or inanimate objects. Proteases have been found localized in the granules of granulocytes in Ornithodoros moubata (Inoue et al. 2001). Whereas gram positive bacteria may be destroyed by defensins secreted from granulocytes (Johns et al. 2000), gram negative bacteria are immobilized in clusters by secretion of lectin-like Dorin-M (Kovar et al. 2000) and surrounded by hemocytes, a non-melanotic encapsulation process known as nodulation (Ceraul et al. 2002).
Fig. 11-7, in Biology of Ticks ISBN:0-19-505910-7.
Small round or ovoid cells contain few, large granules filled with a matrix of fibrillar material. They are similar to type I granulocytes, but are not fusiform and do not show filamentous filopod extensions from the plasma membrane.
Fig. 11-8, in Biology of Ticks ISBN:0-19-505910-7.
Cell type of uncertain status. The literature concerning the occurrence of this type of cell in ticks is unclear. Oenocytoids were reported to occur in Rhipicephalus (=Boophilus) microplus (Silva et al. 2006. Rev. Bras. Parasitol. Vet. 15:128 - 131). Oenocytoids are an important cell type in the hemolymph of insects and are associated with melanotic encapsulation.
Neuroendocrine organs located in the hemolymph adjacent to the synganglia. Two types occur, the retrocerebral organ complex (ROC) and the lateral segmental organs (LSO).
Neurosecretory centers are clusters of two or neurosecretory cell types, cells that fill with neurosecretory granules thatmigrate along the axons of these neurons to the target cells, tissues or organs. Neurosecretory centers are identified byparaldehyde-fuchsin staining. A total of 18 neurosecretory centers have been found in the synganglion, of which 2 are unpaired.
Small cell clusters located in the lateral nerve plexus on the lateral sides of the synganglion. The cells of the LSO exhibitultrastructural characteristics consistent with steroid hormone secreting tissues. The LSO may be associated with hormonal functions. Previously thought to be site for ecdysteroid biosynthesis and secretion, that is now known to be carried out in the epidermisfollowing stimulation by the synganglion (Lomas et al. 1997).
Fiber tracts in the neuropile of the synaganglion that connect the various neurosecretory centers and the retrocerebral organ complex (ROC).
This is the sheath that surrounds the retrocerebral organ complex. It is formed by the fusion of extensions from the neurilemmaand the perineurium. Extensions of this sheath from a neurohaemal sinus that opens into the periganglionic sinus, facilitating the passage of secretions from the ROC into the hemolymph.
adult retrocerebral organ complex vascular sheath
This is the sinus (cavity) formed by the extensions of the vascular sheath surrounding the retrocerebral organ complex (ROC). The neurohaemal sinus opens into the periganglionic sinus around the synganglion.
adult retrocerebral organ complex neurohaemal sinus
A unpaired neurosecretory center located in the supraesophageal region of the syngangion.
A pair of neurosecetory centers located in the supraesophageal region of the synganglion. These paired centers occur just posterior to neurosecretory center number 1.
A pair of neurosecretory centers located in the supraesophageal region of the synganglion. These centers are located along the edge of the protocerebrum lateral to neurosecretory cente rnumber 2.
A pair of neurosecretory centers located in the supraesophageal region of the synganglion. These centers are located along the edge of the postero-lateral part of the protocerebrum posterior to neurosecretory center number 3.
A pair of neurosecretory centers located in the supraesophageal region. These centers are located just anterior to the cheliceral ganglia.
A pair of neurosecretory centers located in the supraesophageal region of the synganglion. These centers are located near thecheliceral ganglia adjacent (lateral) to neurosecretory centers number 5.
A pair of neurosecretory centers located in the supraesophageal region of the synganglion. These centers are located along thelateral edge of the region near the ventro-lateral edge of the protocerebrum.
Fig. 14-2, Fig. 14-5, in Biology of Ticks ISBN:0-19-505910-.
A pair of neurosecretory centers located in the supraesophageal region of the synganglion. These centers are located along the edge of the stomadeal pons.
Fig. 14-2, in Biology of Ticks ISBN:0-.19-505910-7.
A pair of neurosecretory centers located in the supraesophageal region of the synganglion. These centers are located near the anterior edge of this region just above the esophageal nerve.
This plexus occurs along the lateral edge of the synganglion and is formed from branches of the pedal nerve trunks. The lateralsegmental organs (LSO) lie embedded in this plexus.
A pair of neurosecretory centers located in the subesophageal region of the synganglion adjacent to pedal ganglion II.
A pair of neurosecretory centers located along the ventrolateral margin of the subesophageal region of the synganglion adjacent to pedal ganglia I and II.
A pair of neurosecretory centers located along the lateral margins of the subesophageal region of the synganglion adjacent to pedal ganglia II.
A pair of neurosecretory centers located along the lateral margins of the subesophageal region of the synganglion adjacent to pedal ganglia II and III.
A pair of neurosecretory centers located along the lateral margins of the subesophageal region of the synganglion adjacent to pedal ganglion III.
A pair of neurosecretory centers located along the lateral margins of the subesophageal region of the synganglion adjacent to pedal ganglion IV.
A pair of neurosecretory centers located along the postero-ventral margins of the subesophageal region of the synganglion adjacent to the opisthosomal ganglia.
A pair of neurosecretory centers located in the postero-median region of the subesophageal region of the synganglion adjacent to the paired opithosomal ganglia.
A large, unpaired neurosecretory center located in the median ventral part of the subesophageal region of the synganglion.
One of the peripheral nerves from the synganglion to the retrocerebral organ complex (ROC).
A nerve from the synganglion to the center of the retrocerebral organ complex (ROC).
The fluid filled interior of the body, capitulum and legs not occupied by organs or tissues. The hemocoel is filled with hemolymph.
The upper lobe of the retrocerebral organ complex (ROC).
adult retrocerebral organ complex dorsal lobe
The paired ventral regions of the retrocerebral organ complex (ROC).
adult retrocerebral organ complex ventral lobe
A pair of nerves that innervates the dorsal lobe of the retrocerebral organ complex (ROC).
The principal nerve innervating the retrocerebral organ complex (ROC).
Tracheal trunk leading to the capitulum.
adult anterior cerebral anastomosis trunk
The leg segment where the leg is attached to the body. Powerful coxal muscles from the body wall move the coxa and, as aresult, the entire leg in an antero-posterior direction.
The segment of the leg that is attached to the coxa on the proximal side and the femur on the distal side. The trochanter canbe flexed or extended by internal muscles from the coxa to the trochanter. Soft articulatory cuticle occurs between the two joints.
Fig. 4-20, with permission from the editor, Journal of Parasitology.
The segment of the leg that articulates with the trochanter on the proximal side and the tibia on the distal side. Internal leg muscles from the trochanter enable the joint to flex and extend. In some species, the femur may appear to be divided into a basifemur and a telofemur but this is superficial since it is not reflected in the internal musculature.
The segment of the leg that articulates between the femur on the proximal side and the metatarsus on the distal side. Internal muscles from the femur enable the segment to flex and extend so that the leg can be flexed against the body for protection or extendedfor walking.
Region of the leg between the femur and the tibia. Capable of flexion and extension.
Terminal segment of the leg that bears the claws, pulvillus (when present) and the Haller's organ. Some authors subdivide the tarsus into a posterior metatarsus and the anterior tarsus, but this is a superficial separation since there is no joint or muscle distinction.
The apotele comprises the claws and the pulvillus on a hinged joint at the tip of the tarsus. The entire structure is capableof movement, flexing and extending in the same plane (1 degree of freedom).
Fig. 4-21, in Biology of Ticks ISBN:0-19-505910-7.
Pad located at the end of the apotele under the claws. Used for climbing. Absent in argasid adults and nymphs.
Sensory structure located on the dorsal surface of the tarsus. Contains structures used for odor detection and other sensory functions.
A cavity on the dorsal surface of the tarsus of leg I that contains a number of single-walled multiporose olfactosensilla and other apparently non-sensory setae. The sensilla are innervated by as many as 29 sensory neurons. In most ixodid ticks, the roof ofthe capsule has a thin, narrow slit. In a species of the genus Ixodes, the opening is large and circular. In some argasid ticks, the roof of the capsule is perforated with a reticulated lattice instead of a simple roof.
Fig. 4-21; with permission from the editor, Journal of Parasitology, Fig. 4-22, Fig. 15-12, Fig. 15-13, in Biology of Ticks ISBN:0-19-505910-7.
A depression on the dorsal surface of the tarsus of leg I located distal to the posterior capsule. The anterior pit is usuallysurrounded by a prominent ridge. In most ixodid ticks, the anterior pit contains 6 or 7 setiform sensilla, including one or moremultiporose sensilla serving as olfactosensilla, tip pore that serve as gustatory sensilla and still others that are grooved fine andno-pore sensilla that are probably mechanosensilla. At least one of the tip pore setae is a multifunctional sensilla. In Rhipicephalus (= Boophilus) microplus, 3 of the anterior pit sensilla are grooved double-walled porous sensilla with the pores in the grooves while other lackpores. In argasid ticks, the anterior pit typically contains 9 sensilla, although the number is variable among the species. Several multiporose olfactosensilla are recognized, along with grooved sensilla and no-pore mechanosensory setae.
Two or more multiporose setiform sensilla located on the dorsal surface of Tarsus I immediately distal to the anterior pitportion of Haller's organ. Although not technically a part of either the anterior pit or the posterior capsule, these odorant sensilla function in the same role as the odorant sensilla in the body of Haller's organ and, consequently, are considered as functionally part of the organ.
A large multiporose setiform sensillum which functions as a olfactosensory sensillum. This multiporose sensillum has up to 15dendrites. In Amblyomma americanum, this sensillum is innervated by 5 neurons.
adult Haller's organ anterior pit MD-1 sensillum
A large multiporose setiform sensillum which functions as a olfactosensory sensillum. In Amblyomma americanum, this sensillumis innervated by 9 neurons.
adult Haller's organ anterior pit MD2 sensillum
A group of 4 setae (typically) located immediately posterior (proximal) to the posterior capsule of Haller's organ. Function unknown. Although not specifically part of the organ, they are sufficiently close as to form a part of the anatomy of Haller's organ and may contribute to its function.
Fig. 15-10, in Biology of Ticks ISBN:0-19-505910-7.
Setae located in the posterior capsule of Haller's organ. Typically, 4 of the setae are single-walled multiporose sensilla and are innervated by one or more dendrites. As many as 8 other sensilla are simple setiform structures known as pleomorphs that are not innervated.
Pleomorphs: not sensory components of the capsule. Not to be confused with sensory setae.
A small internal gland composed of up to 4 cells located immediately below the Haller's organ within tarsus I.
Fig. 15-11, in Biology of Ticks ISBN:0-19-505910-7.
A tissue comprised of one or more sensory neurons and sheatrh cells (thecogen cells) which secrete an amorphous sheath, the scolopale, that surrounds and insulates the neuron cell bodies and their dendrites. Sheath cells are reported to occur in arachnids (Tichy and Barth 1992: Microsc.Res. Tech. 22: 372-391). Thecogen cells have also been confirmed in the tick Amblyomma variegatum by Steullet (1993, Perception of vertebrate volatiles in the tropical bont tick Amblyomma variegatum; dissertation at the University of Neuchatel, Switzerland).
A cell found in the peripheral sensilla that surrounds the neuron cell bodies and the proximal parts of their dendrites.
An amorphous sheath secreted by the thecogen cells that surrounds the sensory neurons and the proximal parts of their dendrites.
A type of cell found in the sensillum that surround the sensory neuron dendrites and nourishes them; presumably functioning inion transport.
adult peripheral sensilla trichogen cell
Cells that contribute to the formation of the sensillum.
A hair like process that extends from the cuticle to the exterior. The seta is the most common type of sensillum. The seta isinserted into a socket, a depression in the cuticle surrounded by a slight ridge. The interior of the seta is hollow and connected directly to a duct that extends through the cuticle to the epidermis. Several neurons embedded in the epidermis innervate the setiform sensillum, sending dendrites into the shaft of the seta. Axons from the neuron cell bodies extend into the interior of the body and communicate via nerves to the synganglion. Most setae are simple, without pores and serve as mechanosensilla and are innervated by mechanosensory neurons. Specialized setae have either single pores at the tip (gustatory sensilla), pores all over the sensilla (olfactosensilla) or pores in ridges along the side walls or with grooves that lack pores. These latter sensilla are believed to function as hygrosensilla or thermosensilla or both.
Fig. 5-1, Fig. 5-10, in Biology of Ticks ISBN:0-19-505910-7.
The enlarged, rounded or oval cavity on the dorsal surface of the cuticle in which the seta is embedded. The socket is evident externally as a ring of slightly thickened, elevated cuticle.
Fig. 5-10, in Biology of Ticks ISBN:0-19-505910-7.
Slit-like structures that occur on the dorsal surfaces of the second, third and fourth leg tarsi in Amblyomma variegatum. Theyare believed to be mechanosensilla specifically dedicated to detecting airborne or substrate vibrations.
The layer of clear, transparent cuticle that covers the eye.
A region of the subesophageal region of the synganglion that contains neurons that communicate with the eyes via the optic nerves. Axons from the eyes communicate with association neurons in the optic lobes.
Anterior tracheal trunk in the anterior dorsal body region.
Tracheal trunk leading to the anterior lateral margins of the body.
Tracheal trunk leading to the median region of the body.
Tracheal trunk leading to the median dorsal region of the body.
Tracheal trunk leading to the posterior dorsal region of the body.
Tracheal trunks leading to the dorsal anterior region of the body immediately posterior to the capitulum.
Tracheal trunk that extends to the posterior median region of the body.
Tracheal trunk that extends to the legs and subdivides into the indidividual tracheae that supply the legs.
The respiratory tube that supplies air to the organs and tissues and removes CO2.
The cuticular lining of the trachea that is folded into distinctive spiral coil which gives the trachea its distinctive character when viewed with the scanning or transmission electron microscope.
The single layer of epithelial cells that secretes and maintains the tracheae.
A pair tracheae that are derived from the anterior lateral trunks and extend to the chelicerae.
A pair of tracheae derived from the anterior lateral trunk and which extend anteriorly into the basis capituli.
A pair of trachea derived from the posterior median trunk that anastomoses into tiny tracheae throughout the posterior region ofthe body.
The fat body consists of highly dispersed strands of cells clinging to the atrial chamber, tracheal trunks and trachea and, to a limited extent, other internal organs. The fat body is the site of synthesis for vitellogenin, the yolk protein, of conversion o fecdysone into 20-hydroxyecdysone (the molting hormone and other hormonal functions) and probably other functions. It is also believedto be site for the production of antimicrobial proteins, e.g., defensin. The fat body subdivided into central region, surrounding thealimentary canal and a peripheral region, along the tracheal trunks and tracheae. The fat body consists of two types of cells,trophocytes and nephrocytes.
The primary cell type that makes up most of the fat body. Located in groups (chords) of cells attached to the exterior of thetracheal trunks and tracheae throughout the body, capitulum and legs. The trophocytes are considered as the cells responsible forsynthesis and secretion of vitellogenin.
One of the two types of the cells that make up the fat body. Nephrocytes are oval or subcircular cells, often free floating orattached adjacent to the epithelial-like trophocytes. Their precise function is unknown.
The system of striated, voluntary muscles that control the movements of the various parts of the body, capitulum and legs.
Bands of muscles that extend between the inner surfaces of the ventral and dorsal body cuticle that compress the body and create hydrostatic pressure. In argasidticks, the attachment sites are marked by external discs visible on the outer surface of the cuticle.
Muscle bands that rotate the coxa of leg I away the midline of the body.
Fig. 6-4, in Biology of Ticks ISBN:0-19-505910-7.
Bands of muscle that rotate the coxa towards the midline of the body.
Muscle bands that rotate the coxa of leg II away the midline of the body.
Muscle bands that rotate the coxa of leg III away the midline of the body.
Muscle bands that rotate the coxa of leg IV away the midline of the body.
Muscle bands that rotate the coxa of leg II toward the midline of the body.
Muscle bands that rotate the coxa of leg III toward the midline of the body.
Muscle bands that rotate the coxa of leg IV toward the midline of the body.
Muscles that control the movements of the cuticle around the genital pore.
Muscles that draw (flex) the capitulum (gnathosoma) towards the body.
Muscles that extend the capitulum away from the body.
Muscle bands that occur between the coxae.
In argasid ticks, muscles that insert on the coxal fold.
In argasid ticks, muscles that extend from the body wall to the coxal glands.
Muscles that insert on the marginal fold.
In argasid ticks, muscles that insert on the pre-anal groove.
Muscles that extend from the dorsal body wall (scutum in ixodid ticks) to the bases of the chelicerae.
Small muscle that draws the macula against the ostium, closing the spiracular pore.
A portion of the macula, forming its upper lip.
A pair of flap-like structures that allow the opening or closing of the anal aperture.
The portion of the macula that impinges against the spiracular plate, thereby closing the ostium (spiracular pore).
The minute submicroscopic tubes that penetrate directly into the cells and tissues. Tracheoles are the final terminal endings of the tracheae.
The columella is the portion of the macula adjacent to its junction with the ostium.
The thin section of cuticle that connects the columella to the underside of the cuticular layer that supports the pedicels. The columella extends from the upper lip of the macula to the underside of the pedicels.
In argasid ticks, the valve-like constriction between the atrial chamber and the subostial space of the spiracle.
In argasid ticks, a enclosed area near the pedicels and connected to the subostial space. The roof of the vestibulum isflexible and can be everted or inverted, thereby controlling gaseous pressure into the tracheal trunks. In Exp. Appl. Acarology:14:151-163.
This system consists of the ovary, the oviducts, the uterus, the cervical vagina, the seminal receptacle, the vestibular vagina,accessory glands and the genital pore. In addition, Gene's organ, located separately in the dorsal body cavity, serve as the eggwaxing organ.
An organ located in the dorsal anterior region of the body with paired horns that can be extruded through the capitular foramen in the camerostomal fold. Gene's organ is responsible for coating the eggs with a waxy secretion.
Fig. 16-22, in Biology of Ticks ISBN:0-19-505910-7.
The opening at the anterior end of the body through which the finger-like projections of the Gene's organ extend.
The raised margins of the camerostome. It is comprised of folded cuticle.
Fig. 4-27, in Biology of Ticks ISBN:0-19-505910-7.
Muscles from the dorsal interior of the body that insert on the horns of the Gene's organ. These muscles withdraw the horns ofthe organ back into the body when not in use.
In each leg the muscle that extends from the coxa which bends the trochanter and folds it against the body.
Fig. 6-4, Fig. 6-5, in Biology of Ticks ISBN:0-19-505910-7.
In each leg, a muscle band that extends from the coxa to the trochanter and extends it away from the body.
In each leg, a muscle band that extends from the trochanter to the femur and bends it towards the body.
Fig. 6-5, in Biology of Ticks ISBN:0-19-505910-7.
In each leg, the band of muscle that extends from the trochanter into the femur and extends it away from the body.
In each leg, the muscle band that extends from the femur to the patella and bends it towards the body.
In each leg, the muscle band that extends from the femur into the patella and extends it away from the body.
In each leg, the band of muscle that extends from the patella into the tibia and bends it towards the body.
In each leg, the band of muscle that extends from the patella into the tibia and extends it away from the body.
In each leg, a band of muscle that extends from the tibia into the tarsus and bends it towards the body.
In each leg, a band of muscle that extends from the tibia into the tarsus and extends it away from the body.
In each leg, the band of muscle that extends from the tarsus and inserts on the pretarsus, bending it towards the tarsus.
In each leg, the band of muscle that extends from the tarsus, inserts on the pretarsus and moves it away from the leg (extendsit outwards).
The posterior cuticlelined sac that surrounds the internal body of Gene's organ. The cuticular-lined sac encloses the corpus and the horns of the organ (Schol et al. 2001).
Fig. 1-EAA, Fig. 3-EAA, Fig. 4-EAA, Fig. 8-EAA, in Exp. Appl. Acarol. 25: 327-352.
The corpus is the large sac at the posterior end of the gland that fills with fluid. It is supplied with ducts from the adjacent glands. Evidently, this is the main repository of waxy secretions that are poured onto the eggs.
Fig. 1-EAA, Fig. 2-EAA, Fig. 6-EAA, Fig. 9-EAA, in Exp. Appl. Acarol. 25: 327-352.
A pair of antero-lateral lobe or finger-like projections that are everted during egg waxing. These blind-ending horns are everted by hydrostatic pressure of the hemolymph. In Prostriate ticks, 4 horns are present.
Fig. 1-EAA, Fig. 2-EAA, Fig. 9-EAA, Fig. 17-EAA, Fig. 18-EAA, Fig. 19-EAA, Fig. 20-EAA, in Exp. Appl. Acarol. 25: 327-352.
The outermost part of Gene's organ which secretes the cuticular sac and is continuous with the epidermis of the body and capitulum. It also forms the corpus and blind-ending horns.
Fig. 1-EAA, Fig. 4-EAA, Fig. 8-EAA, Fig. 11-EAA, Fig. 22-EAA, Fig. 23-EAA, in Exp. Appl. Acarol.25: 327-352.
Accessory glands that occur on either side of the Gene's organ. The main efferent ducts of these glands open into the lumen between the epithelial sac and the cuticular sac into the corpus (Schol et al. 2001).
Fig. 2-EAA, Fig. 6-EAA, Fig. 7-EAA, Fig. 9-EAA, in Exp. Appl. Acarol. 25: 327-352.
Accessory glands that occur on either side of the Gene's organ. The main efferent ducts of these glands open into the lumen between the epithelial sac and the cuticular sac into the horns (Schol et al. 2001).
Fig. 2-EAA, Fig. 9-EAA, in Exp. Appl. Acarol. 25: 327-352.
Accessory glands associated with the Gene's organ that secrete waxy fluids via main efferent ducts into the organ. Kuhn et al. describe reported lectin activity in the "invaginations of the Gene's organ" suggesting that lectins play a role in protecting the eggs against microbial invasions (Schol et al. 2001).
Fig. 1-EAA, Fig. 8-EAA, in Exp. Appl. Acarol. 25: 327-352; Also in Parasitol. Res. 82: 215 -221.
The opening at the posterior end of the organ. The Gene's organ is open to the hemocoel and hemolymph circulates into the organ, contributing the hydrostatic pressure that everts the gland during egg waxing activity. From Schol et al. (2001).
Fig. 1-EAA, in Exp. Appl. Acarol. 25: 327-352.
The main duct that carries the secretions of the Gene's organ tubular glands to the lumen between the epithelial sac and the cuticular sac surrounding the corpus and horns.
Fig. 8-EAA, Fig. 10-EAA, Fig. 11-EAA, Fig. 12-EAA, in Exp. Appl. Acarol. 25: 327-352.
The lumen between the epithelium of the epithelial sac and the cuticular sac. This is the lumen into which the secretions of the accessory glands accumulate and presumably migrate into the corpus and horns when the gland is everted to wax the eggs (Schol et al. 2001).
Fig. 1-EAA, Fig. 3-EAA, in Exp. Appl. Acarol. 25: 327-352.
Numerous pits located on the surface of the cuticular sac. Each pit contains a pore joined to tubuli that open into the lumen between the cuticular and epithelial sacs.
Fig. 3-EAA, Fig. 5-EAA, in Exp. Appl. Acarol. 25: 327-352.
These pores are the openings of the tubuli that permeate the cuticle of the cuticular sac and allow waxy secretions to spread out over its surface when the horns are everted.
Fig. 5-EAA, in Exp. Appl. Acarol. 25: 327-352.
Elongated (247.5 nm) submicroscopic tubes that permeate the walls of the cuticular sac, opening into the cribate pores on theexternal side of the cuticular sac and the lumen between the epithelial and cuticular sacs on the internal side.
Folds (mean height 5.9 microns) in the epicuticular surface of the external side of the cuticular sac in the lateral regions ofthe corpus and horns. These ledge-like structures give the horns and the lateral regions of the corpus its folded appearance when theeverted organ is viewed with the Scanning electron microscope (SEM) (Schol et al. 2001).
The blind ending extension of the tubular glands, cranial glands and caudal glands.
Fig. 1-EAA, Fig. 10-EAA, in Exp. Appl. Acarol. 25: 327-352.
The fluid filled duct of the tubular end pieces of each gland that empty into the main efferent ducts (Schol et al. 2001).
Fig. 11-EAA, in Exp. Appl. Acarol. 25: 327-352.
adult Gene's organ tubular endpiece central excretory duct
The cells that line the tubular end pieces and secrete the amorphous waxy fluid that flows into the ducts and eventually out on to the horns to wax the eggs. Each gland cell secretes into its own individual lumen and is connected to a cuticular pore by a duct cell.
Fig. 10-EAA, Fig. 11-EAA, in Exp. Appl. Acarol. 25: 327-352.
adult Gene's organ tubular end piece gland cell
Innumerable tiny delicate cuticular folds that cover the surfaces of the horms of the Gene's organ (Schol et al. 2001).
Fig. 17-EAA, Fig. 18-EAA, Fig. 19-EAA, Fig. 20-EAA, Fig. 21-EAA, in Exp. Appl. Acarol. 25: 327-352.
The fluid filled cavity within which waxy secretions flows into the main duct of the gland (Schol et al. 2001).
Fig. 9-EAA, in Exp. Appl. Acarol. 25: 327-352.
adult Gene's organ exceretory duct lumen
Duct cells are cells that connect the secretory glandular cells to the cuticular pores of the cuticular sac (Tissue and Cell 16: 589-599).
Fig. 10-EAA, in Exp. Appl. Acarol. 25: 327-352.
adult Gene's organ tubular end piece duct cell
The epithelial layer that secretes the atrial chamber wall.
The cuticle that forms the inner wall of the atrial chamber.
Openings (pores) on the epicuticular surface of the cuticular sac. These pores are the openings of the tubuli in the wall of the cuticular sac. The tubuli pass through the cuticular sac and end in pores on the epicuticular surface and open into the lumen between the epithelial sac and the cuticular sac. The arrangement is similar in both argasid and ixodid ticks.
The ductular zone comprised of numerous ducts connecting the secretory lobes of the foveal gland with the foveal pores.
Fig. 19-16, in Biology of Ticks ISBN:0-19-505910-7.
The ampullae are cap-like structures that connect the foveal ducts in the cuticle with the gland ducts below the cuticle. Each ampulla is composed of an electron dense outer zone with flap-like ends that enclose the structure like a cap, and a more lucent innerzone where each duct from the secretory lobes is inserted.
The pair of porose areas located on the dorsal surface of the body in adult ixodid ticks. In females, the paired foveae arelocated in the mid-alloscutal part of the dorsum immediately posterior the scutum. Each fovea contains from 15 - 50 slit-like poresin a circular field surrounded by a narrow circular ridge. The external pores communicate with the foveal ducts the permeate thecuticle below the structure. In males, far fewer slits occur and there is no circular ridge. Foveae dorsales are absent in juvenilestage ticks and in argasid ticks.
The single layer of cuboidal epithelial cells that forms the wall of this tube.
The thin layer of squamous or cuboidal cells that forms the wall of the rectal sac.
The thin layer of squamous epithelial cells that secretes the cuticle lining of the rectum.
A spine located on the dorsal surface of the inner cheliceral digit.
adult inner cheliceral digit dorsal spine
A band or u-shaped crescentic tube stretched horizontally across the posterior region of the body. The ovary is studded withinnumerable oocytes that expand in size during oogenesis, fill with brown yolk (vitellogenin) after mating and eventually migrate outinto the oviducts and vagina to exit the body. The ovary appears as a delicate, white tube in unfed females but becomes veryprominent during feeding, eventually appearing as one of the largest organs in the body. The ovary is similar in both ixodid andargasid ticks. In D. andersoni, the ovary is approximately 6 mm long by 64 - 110 microns in diameter. The tick ovary is of thepanoistic type, i.e., it lacks nurse cells.
Undifferentiated cells that form the epithelial lining and occur between the oogonia or developing oocytes. Comparable to stemcells.
The earliest developmental stage cells that will become oocytes. Oogonia are committed cells that have not yet begun to fullydevelop into oocytes.
Fig. 16-8, in Biology of Ticks ISBN:0-19-505910-7.
The outer layer of squamous epithelial cells and smooth muscle cells that surrounds the ovary and forms its wall. Lies againstthe epithelial layer.
The tunica propria is the amorphous lamellate sheath comprised of multiple layers of fibrillar material, collectively about 1micron thick. The tunica propria extends (folds) around each of the developing oocytes and forms an outer covering as they enlarge. The tunica propria is believed to be permeable to vitellogenin and other hemolymph proteins.
The tube-like cavity (lumen) of the ovary. Lined by the lumenal epithelium. The ovarian lumen is continuous with the oviducts. Fully developed oocytes pass into the lumen and migrate to the oviducts for eventual passage out of the reproductive system.
The layer of epithelial cells, mostly interstitial cells interspersed with oogonia, that forms the inner lining of the ovary.
An elongated depression on one side of the length of the ovary. Germinal cells in the longitudinal groove are generally less well developed than elsewhere in the ovary; this appears to be a region of slower developmental activity.
These are the earliest stage in the development of the oocytes that appears soon after attachment and the commencement offeeding in ixodid ticks or soon after the blood meal in the fast feeding argasid ticks. Stage I oocytes bulge externally on the outersurface of the ovary, appearing larger than the interstitial cells but with little additional cytoplasm. Stage I oocytes areprevitellogenic (i.e., lack yolk).
Stage II oocytes are considerably larger than the stage I oocytes and constitute the next stage in their development. They continue to enlarge, with a much greater increase in cytoplasm during the slow feeding phase in ivirgin ixodid ticks or post-feedingbut prior to mating in argasid ticks. Stage II oocytes bulge externally on the outer surface of the ovary, appearing much larger than the interstitial cells or stage I oocytes. Stage II oocytes are also previtellogenic (i.e., lack yolk) cells and remain white in color.
Fig, 16-8, in Biology of Ticks ISBN:0-19-505910-7.
Stage III oocytes constitute the developmental stage of the oocytes when they first begin to acquire yolk. Following mating,high levels of ecdysteroid (20-hydroxyecdysone) stimulate vitellogenin production in the fat body and, simultaneously, upregulation of the vitellogenin receptors in the oocytes (Thompson et al. 2007; Mitchell et al. 2007). As a result, the enlarging oocytes now begin to acquire yolk granules and begin to turn brown in color (vitellogenin is a lipoglycoheme protein). The stage III oocytes are larger than the stage I or stage II oocytes and are easily distinguished by their brown color.
The greatly enlarged oocyte filled with enormous masses of yolk spheres. Shell formation begins at this stage. A micropyle ispresent in this stage, through which spermatozoa can enter the oocyte for fertilization.
The final stage in oocyte development. At this stage, the oocyte passes through the funiculus, the tiny tube attaching it tothe ovary wall, and into the lumen. Many stage V oocytes have already been fertilized and covered with a fully formed shell, i.e., it is now an egg (but not embryonated). This passage of the stage V oocyte into the ovary lumen constitutes ovulation.
The funiculus is the narrow tube through which the fully developed stage V oocytes passes into the lumen of the ovary (ovulation).
The cells that form the funiculus. Typically, two or more cells form this structure.
The long coiled tube connecting the ovary with the uterus. In argasid ticks, the oviducts expand near their junction with the uterus, forming a bulbous ampulla.
The sclerotized outer covering of the egg.
The tiny groove-shaped opening at the end of the developing stage IV oocyte through which mature spermatozoa may enter theoocyte for fertilization. The micropyle is adjacent to the funiculus.
The lining of the oviduct consists of a thin layer of mostly cuboidal epithelial cells about 25 - 40 microns throughout most ofthe length of this structure. The outer wall consists of a basal lamina and a thin connective tissue membrane with occasional smoothmuscle cells arranged circumferentially around the duct. In feeding ticks, the epithelial lining expands as a result of celldivisions and becomes several layers thick.
Fig. 16-2, in Biology of Ticks ISBN:0-19-505910-7.
The outer wall of the oviduct surrounds the epithelial layer. The outer wall consists of a thick basal lamina and a thin connective tissue membrane with occasional smooth muscle cells arranged circumferentially around the duct.
Fig. 16-7, in Biology of Ticks ISBN:0-19-505910-7.
In argasid ticks, the oviducts expand into large thick bulbous structures near the point where the oviducts merge with theuterus. The walls of the ampullae are considerably thicker than the other regions of the oviduct. The function of the ampullae is unknown. Ampullae have not been reported to occur in ixodid ticks.
The uterus is the region of the female reproductive track between the oviducts and the vagina. The uterus is much moreprominent in argasid ticks. In ixodid ticks, is a short tube between the oviducts and the distally located connecting tube. The lining of the uterus is similar to the oviducts.
The lining of the uterus is formed of a thin layer of cuboidal cells similar to that of the oviducts.
The outer wall of the uterus resembles the structure of the outer wall of the oviducts, with a delicate basal lamina, connectivetissue fibers and occasional smooth muscle cells.
In ixodid ticks, the uterine connecting tube is a short, narrow duct that connects the uterus to the cervical vagina. The innerwall is lined with a thin layer of cuticle, 2 - 3 microns thick. The outer wall is comprised of thin layer of epithelial cellscovered by smooth muscle cells.
The thin (2 - 3 microns thick) layer of cuticle that lines this structure.
adult uterine connecting tube cuticular lining
The thin layer of epithelial cells that forms part of the wall of the connecting tube. The cells are mostly squamous orcuboidal. These cells secrete the cuticular lining.
adult uterine connecting tube epithelial layer
The layer of smooth muscle cells that surround the connecting tube. The muscle layer is approximately three or four cells thick.
adult uterine connecting tube muscle layer
The cervical vagina is the thick muscular zone of the vagina. The cervical vagina is lined with a thick layer of highly foldedcuticle some 13 - 25 microns thick, a thick complex epithelium of cuboidal and tall columnar cells and, finally, an especially layerof smooth muscle. The cervical vagina opens into the vestibular vagina at its anterior end, the connecting tube at itspostero-ventral end and the seminal receptacle at its posterodorsal end. The cervical vagina serves as the organ responsible forexpelling the eggs from the reproductive tract, i.e., it functions as an ovipositor, during oviposition.
In ticks, the cervical vagina is lined with a relatively thick zone of highly folded, labyrinthine cuticle about 13 - 25 microns thick.
The epithelium of the cervical vagina is many cells thick, comprising both cuboidal and tall columnar cells that appear to behighly interdigitated with one another.
A thick band comprised of mutiple layers of smooth muscle cells that form the outer layer of the wall of the cervical vagina. The muscle mass here is thicker than in any other part of the female reproductive system, indicating its importance in expelling theeggs during oviposition.
Cuboidal cells are one of the two most common types of cells that form the epithelial layer of the cervical vagina. These cellsinterdigitate with the tall columnar cells that are the second most common type.
adult cerviceal vagina epithelial cuboidal cell
The tall columnar cells are one of the most common types of cells that comprise the epithelium of this organ. These cellsinterdigitate with the cuboidal cells, the other most common type. Microvilli appear on the luminal boundaries of the proximal cells,i.e.,the cells adjacent to the cuticular lining. The basal plasma membrane of these cells is highly folded.
adult cervical vagina epithelial columnar cell
The large, folded sac-like organ lying just above (dorsal) the cervical vagina and the connecting tube. It is connected to theposterior end of the cervical vagina.
The narrow channel within the oviducts that will contain the ova as they migrate down the oviducts to the uterus.
The internal cavity within the uterus where the ova are stored until ready to be discharged from the vagina. The uterine lumenis a large area in argasid ticks, but small in ixodid ticks.
This is the thin layer of cuticle, approximately 1 - 2 microns thick, that lines the inner sides of this organ. The innercuticular lining is contiguous with the cuticular lining of the cervical vagina.
Fig. 16-15, in Biology of Ticks ISBN:0-19-505910-7.
adult seminal receptacle cuticular lining
The epithelium of the seminal receptacle is multi-layered with many large cuboidal cells containing huge nuclei, some as largeas 30 microns. These cells enlarge greatly after the female is inseminated and show ultrastructural features characteristics ofsecretory activity. The nature of the secretions is unknown. Other smaller cells also occur.
adult seminal receptacle epithelial lining
The central cavity of the seminal receptacle where the spermatozoa are stored following insemination by the male aftercopulation. Masses of spermatozoa emerge from the seminal receptacle cavity and migrate up the oviducts to fertilize the ova.
The vaginal lumen is the cavity at the center of the organ. Fertilized eggs pass into the cervical vagina and are expelled bythe powerful constrictor muscles surrounding its wall. The lumen of the cervical vagina enlarges to allow egg passage.
The vestibular vagina is the elongated, rounded tube that connects the muscular cervical vagina to the female genital pore. In ixodid ticks, it is approximately 320 - 360 microns long. It is somewhat shorter in argasid ticks. The vestibular vagina is lined with cuticle folded into trabeculae thereby forming a thick layer about 15 - 20 microns across. A thin layer of epithelial cellssurrounds the cuticular lining. In ixodid. Tthe vestibular vagina is surrounded by a multilobed glandular epithelium, the lobular accessory gland. This gland is absent in argasid ticks. A pair of tubular accessory glands are located at the junction ofthe vestibular vagina with the cervical vagina and empty into the vagina at this juncture. In ixodid ticks, the vestibular vaginaenlarges greatly during oviposition, the walls thin and stretch and the tube functions as a primitive ovipositor, assisting in propelling the egg from the vagina out through the genital pore.
The vestibular vagina is lined with a thin layer of cuticle which is folded into deep folds about 15 - 20 microns thick termedtrabeculae. The trabeculae resemble the villi of the vertebrate intestine. These thick folds increae the surface area of thecuticular lining.
adult vestibular vagina cuticular lining
The trabeculae constitute the thick folds of the cuticular lining resembling the villi of the human intestine.
This is the thin layer of epithelial cells that secretes the cuticular lining of the vestibular vagaina.
The vestibular sinus is the space between the vestibular vagina and the surrounding lobular accessory gland.
adult vestibular vagina vestibular sinus
This is the cavity of the vestibular vagina. The lumen is a flattened space in the unfed or previtellogenic tick, some 10 - 20 microns in width and approximately 150 microns in length. It expands during the post-vitellogenic and ovipositional phases of tick reproductive activity.
The tubular accessory glands (TAG) are a pair of glandular structures located at the junction of the cervical vagina with thevestibular vagina. They are present in both ixodid and argasid ticks. Each gland consists of a narrow neck-like section, resemblinga duct, and a broad,bulbous or vermiform glandular region that constitutes the major portion of the gland.
This is the narrow neck-like region of the gland that serves as the connecting duct between the bulbous glandular portion of the gland and the point where it joins the junction of the cervical and vestibular vagina.
The duct zone of the tubular accessory gland (TAG) is lined with a very thin (0.3 microns) layer of cuticle.
The epithelium of the tubular accessory gland duct zone consists of a thin, one cell thick layer of cuboidal epithelial cells. These cells secrete the cuticular lining.
The small, subcircular cavity of the duct zone that connects with the junction of the vestibular vagina and the cervical vagina.
This is the broad, thick vermiform region of the gland filled with large glandular epithelial cells and their supporting cells.
This consists of several layers of large, cuboidal secretory cells and stellate (non-secretory) support cells. In feeding females, these cells multiply and expand greatly in size. The secretory cells are filled with masses of proteinaceous material at the apical ends of the cells. The apical cell surfaces have masses of microvilli that protrude into the lumen. A thin connective tissue layer with a few smooth muscle cells surrounds the epithelium and forms the outer wall of the TAG.
These are the cells that secrete masses of proteinaceous material into the TAG duct. The identity of the proteins that constitute these materials is unknown.
Fig. 16-18, in Biology of Ticks ISBN:0-19-505910-7.
These cells are non-secretory cells that occur in the glandular portion of the TAG. Their role is unknown.
The outer wall of the glandular portion of the TAG is covered by a thin layer of connective tissue fibers and ocassional smoothmuscle cells.
The lobular accessory gland (LAG) is found only in ixodid ticks. The LAG surrounds the vestibular vagina, separated from it by a vestibular sinus (VS). The LAG consists of a bulblous three-lobed gland about 150 microns thick surrounding the vestibular vagina. Numerous ducts permeate the lobes of the gland and fuse with the VS. The secretory cells of the LAG are filled with lipids. Although the function of the LAG is unknown, it is believed to produce a lipid rich secretion that coats the eggs as they pass through the vestibular vagina during oviposition.
The secretory cells form the major portion of the LAG. Most are tall columnar epithelial cells. In feeding virgin females, thesecretory cells contain numerous mitochondria and extensive development of the rough endoplasmic reticulum and ribosomes, features characteristic of secretory activity. However, no evidence of lipid droplets were reported, although this may be related to the timeof collection (i.e., perhaps this might have been found if samples were taken during oviposition). According to Lees and Beament (1948), these cells produce a lipid-rich secretion which coats the eggs as they pass along the vestibular vagina during oviposition, but this could not be confirmed in later studies.
Fig. 16-21, in Biology of Ticks ISBN:0-19-505910-7.
Multiple ducts are found within the lobes of the LAG. These ducts lead from the lobular portion to the vestibular sinus surrounding the vestibular vagina and separating that organ from the LAG.
This system consists of the paired, tubular testes, the paired, convoluted vasa deferentia, a single seminal vesicle, the ejaculatory duct, the massive, multi-lobed male accessory gland and the genital pore. The system is similar in both ixodid andargasid ticks.
Most ticks have a pair of elongated, tubular testes connected near the midline of the body by a thin isthmus. Each testis is a tubular organ comprised of layers of germinal cells surrounded by a thin connective tissue membrane and occasional smooth muscle cells. Interstitial cells occur primarily along the luminal border, according to Raikhel (1983). Spermatogonia, primary and secondary spermatocytes are grouped into clusters termed spermatocysts. Each cluster contains 32 - 64 secondary spermatogonia or spermatocytes, depending upon their position in the testis, and surrounded by a narrow lumen.The testes enlarge greatly during feeding.
The small number of setae, typically two pairs, located on the ventral surface of the basis capituli just posterior to the origin of the hypostome.
The auriculae are a pair of spines that project posteriorly from the ventral surface of the basis capituli. One auricula occurson each postero-lateral surface. Differences in the length and shape of the auriculae are useful taxonomic characters fordistinguishing species.
A small posteriorly projecting spine located on the posterolateral edge of palpal article I of each palp.
The folds located on the ventrolateral margins on each side of the basis capituli.
The deep fold located on the ventral surface of the basis capituli that extends horizontally across this structure.
The cornuae are spines located at the posterolateral margins on the dorsal surface of the basis capituli. The shape and lengthof the cornuae are useful taxonomic characters for distinguishing secies.
Characteristic of ticks of the genus Argas. The line or groove at the lateral margin of t he body separating the doral andventral regions. Absent in other genera of Argasidae and Ixodidae.
Fig. 2-18, in Biology of Ticks ISBN:0-19-505910-7.
Tiny flat, shiny folds on the surface of the integument in ticks of the genus Antricola, giving it the appearance of a tuberculated cuticle. Not present in other genera of argasid ticks or in Ixodidae.
Fig. 2-28, in Biology of Ticks ISBN:0-19-505910-7.
The smooth, shinny region on the dorsal surface resembling the scutum.
Ball and socket joints are a unique feature of the legs of Nuttalliella namaqua, the only species of the family Nuttalliellidae. This feature has not been reported in other acarines and may be unique for the entire subclass.
Fig. 2-36, in Biology of Ticks ISBN:0-19-505910-7.
In argasid ticks, a narrow cone-shaped anterior extension of the body as seen from the dorsal surface.
Fig. 2-21, in Biology of Ticks ISBN:0-19-505910-7.
The arrangement of the denticles (= teeth) on the hypostome in longitudinal files, e.g., two rows on either side of thehypostomal groove = 2/2 dentition, three rows = 3/3 dentition, etc.
These are small ridges or slightly recurved projections instead of teeth or true denticles on the hypostome, usually innon-feeding males. Crenulations may also occur beyond the denticulate zone in some species where the hypostome also bears prominentdenticles.
Dorsal humps are prominent elevations on the dorsal surface of the tarsus in many species of argasid ticks. Dorsal humps occasionally occur on other leg segments.
These are pits that occur on the surface of sclerotized plates, primarily on the scutum.
These are germinal cells that differentiate into spermatogonia.
These are clusters of spermatogonia along with primary and secondary spermatocytes surrounded by a thin-walled epithelium. Each spermatocyst contains from 32 - 62 cells. Near the anterior ends of the testes, elongated spermatids (prospermia) may also populate these structures.
The thin layer of epithelial cells that encloses the masses of spermatogonia and spermatocytes.
These are the cells that represent the earliest stage in the process of spermatogenesis. Spermatogonia are diploid cells that are committed to become spermatocytes and, eventually, fully developed spermatozoa.
The outer wall of the testis consists of a thin connective tissue membrane with occasional smooth muscle cells.
This is the narrow central cavity of the tubular testis.
Fig. 17-5, in Biology of Ticks ISBN:0-19-505910-7.
The isthmus is a thin band of epithelial cells that connects the paired testes. It is located in the midline of the posteriorregion of the body between the two testes.
The peritrophic membrane is an amorphous, proteinaceous membrane that appears several days after the commencement of feeding. It has been conclusively demonstrated in Ixodes scapularis and is assumed to occur in most, if not all species of ticks. This membrane forms a barrier between the delicate epithelial lining of the midgut and the lumen, making it difficult for invasive microbes to penetrate the midgut.
Vol. 2. Fig. 26-7, in Biology of Ticks ISBN:0-19-505910-7.
These are the elongated spermatids that have undergone reduction division. These extremely elongated, haploid spermatids arenot capacitated, i.e., they are not yet capable of fertilizing the oocytes. In this form they migrate to the ejaculatory duct andinto the developing spermatophore whereupon they are transported to the vagina of the female. Capacitation of the inseminated prospermia takes place in the reproductive tract of the female.
The paired vasa deferentia are a paired of coiled, twisted tubules that extend from the anterior (proximal) end of each testis to the seminal vesicle. The vasa deferentia connect the testes to the single seminal vesicle.
The lining epithelium consists of a thin layer of squamous epithelial cells when the duct is empty of sperm cells, or thicker,cuboidal cells when the duct is filled with sperm.
adult lining epithelium of the vas deferens
This is the narrow central cavity of the tubular vas deferens.
The common cuticle-lined duct formed by the union of the paired vasa deferentia tgat leads from those organs to the male genital aperture.
The thin layer of cuboidal cells that forms the wall of the duct. Occasional smooth muscle cells surroud the duct but do notform a muscle layer.
adult ejaculatory duct lining epithelium
A thin, folded layer of cuticle several microns thick that lines the inner surface of the ejaculatory duct.
Fig. 9-3, in Biology of Ticks ISBN:0-19-505910-7.
The narrow internal cavity of the ejaculatory duct.
The rectum is lined with a relatively thick layer of cuticle.
The thin band of cuticle that forms the inner most lining of the esophagus.
The narrow internal cavity of this simple duct.
The internal cavity of the rectal sac. The lumen is usually found filled with masses iridescent or white-appearing spheroidal guanine crytstals. During or soon after feeding, the lumen will also be filled with black-colored hematin wastes or, less often, with red-colored wastes due to undigested hemoglobin.
This is the narrow internal cavity of this short duct.
The anal aperture is the opening between the valves. Wastes from the rectum passes out of the body via the anal aperture.
The thin layer of cuticle that separates the epithelium of the pharyngeal wall from the lumen.
The thin layer of squamous cells that secretes the cuticular lining of the pharynx. The epithelium is surrounded by circularmuscle cells, so that it is virtually unnoticed due to the more prominent musculature.
The very large, multilobed gland in the center of the body, with connections to the vasa deferentia and the seminal vesicle. The male accessory gland is responsible for the production of the seminal fluid and formation of the spermatophore (For histology of the gland, see Figures 17.9 and 17.10, Biology of Ticks, 0-19-505910-7).
The unpaired ventral granular lobe is the largest lobe of the male accessory gland in both ixodid and argasid ticks.
This is a large, unpaired lobe on the dorsal side of the male accessory gland. This is the second largest lobe, second only tothe ventral granular lobe. The dorsal granular lobe is found in both argasid and ixodid ticks.
A pair of small lobular projections from the antero-dorsal region of the dorsal granular lobe of the male accessory gland inixodid ticks.
Fig. 17-1, in Biology of Ticks ISBN:0-19-505910-7.
This is a pair of elongated, lateral projections that extend from the lateral margins of the dorsal granular lobe of the male accessory gland in ixodid ticks.
The pair of small projections that extend from the dorso-lateral margins of the dorsal lobe of the male accessory gland in ixodid ticks.
A pair of elongated, tube-like projections that extend from the main body of the male accessory gland of ixodid ticks and project posteriorly.
A pair of elongated, tube-like extensions of the ventral granular lobe of the male accessory gland in ixodid ticks.
The cell type in the lobes of the male accessory gland that primarily contain electron dense granules.
adult male accessory gland dense granule cell
These cells occur in the granular lobes. They contain 1) large granules, known as complex granules because they are filled withnumerous fine particles, often dispersed in a reticulate pattern AND 2) in addition, electron dense homogeneous granules. The latterare probably lipid-filled granules.
adult male accessory gland mixed granule cell
The epithelial covering of the lobes of the male accessory gland is comprised of large cuboidal and tall columnar cells. In feeding or fed males, cells from the epithelial covering proliferate, become large cuboidal or tall columnar cells that fill with masses of simple and or simple and complex granules.
adult male accessory gland epithelial wall
The spongy lobe of the male accessory gland is the only lobe that lacks granule-filled cells.
Fig. 17-4, in Biology of Ticks ISBN:0-19-505910-7.
In some species of argasid ticks (e.g., Ornithodoros kelleyi), the uterus is very large and bifurcated into a pair of posteriorly-directed horns, the uterine horns. Uterine horns are absent in ixodid ticks and the uterus is generally quite small.
These cells appear in late stage nymphs of argasid ticks and during nymphal development (following feeding) in ixodid ticks. Primary spermatocytes undergo the great growth phase in Prostriate and argasid ticks without the need for feeding. They transform into prospermia (spermatids) which have undergone reduction division.
The sclerotized flap or plate that covers the genital aperture in the adult male. This flap opens to allow the spermatophore toemerge. Not to be confused with the pre-genital plate that occurs in the males of many prostriate ixodid ticks.
Fig. 4-8, in Biology of Ticks ISBN:0-19-505910-7.
The spermatophore is not a permament part of the male anatomy. Rather it is formed externally from soluble proteins, lipids and other materials in a viscous droplet ejaculated by the male during copulation. These materials coagulate into the ectospermatophore that momentarily encloses the male genital aperture. This is followed quickly by masses of elongated prospermia and seminal fluids that flow into the ectospermatophore, causing it to balloon and turn opaque. Next, a second viscous droplet is introduced which forms the bilobed endospermatophore. This also seals the spermatophore. A single endospermatophore occurs in ixodid ticks, but two endospermatophores commonly occur in argasid ticks. When completed, the entire spermatophore is seized by the male's chelicerae as itemerges from the male genital aperture. Then, using its chelicerae, the male transfers the spermatophore to the female's genital aperture and implants it into the vestibular vagina. Saliva is secreted to lubricate the female's genital area to facilitate the process. Meanwhile, CO2 generated within the spermatophore creates sufficient pressure to force the masses of elongated prospermia and semen into the endospermatophore (s), which everts, expands and passes out the external spermatophore and into the female's genital tract. The ectospermatophore remains as an empty sac on the external surface of the female, where it soons dries, shrivels and falls off.
Fig. 17-6, in Biology of Ticks ISBN:0-19-505910-7.
This is the temporary external sac of the spermatophore. It does not enter the female genital tract but, rather, shrivels and falls away after copulation.
The temporary proteinaceous sacs that will carry the masses of greatly elongated prospermia into the female's genital tract. Initially contained within the spermatophore, the single (Ixodidae) or pair (Argasidae) of endospermatophores will pass into the female.
Fig. 17-16, in Biology of Ticks ISBN:0-19-505910-7.
The wall of the esophagus is a thin layer of squamous and cuboidal epithelial cells.
Fig. 14-8, in Biology of Ticks ISBN:0-19-505910-7.
A pair of glands situated on either side of the Gene's organ in ixodid ticks. Each gland consists of a single acinus comprising 8 - 12 cells. Each cell is connected via an individual duct to pores on the dorsal surface of the basis capituli. Each cell isconnected to a cuticular pore by a duct cell. The secretions of the accessory gland cells are incorporated into the egg wax during oviposition (From Tissue and Cell, 1984, 16: 589 - 599).
The secretory cells that comprise the accessory glands. These gland cells contain striking quantities of smooth endoplasmic reticulum and numerous Golgi dictyosomes and appear to secrete lipids onto the cuticular surface. These lipids become incorporated into the egg wax.
The pores on the dorsal surface of the basis capituli through the secretions of the acinar cells are passed to the external surface (Tissue and Cell 1984, 16: 589 - 599).
These are cells that connect the acinar cells of the gland to the cuticular ducts through which the cell secretions are passed to the exterior (Tissue and Cell 1984, 16: 589 - 599).
adult Gene's organ accessory gland duct cell
Small glands found below the spiracular plate in ixodid ticks. These secrete waxy secretions to the exterior by way of pores in the spiracular goblets. See Walker et al. (1996) Integumental glands of the tick Rhipicephalus appendiculatus (Acari: Ixodidae) as potential producers of semiochemicals. J. Med. Entomol. 33: 749 - 759.
The tiny openings in the spiracular goblets through which the secretions from the spiracular glands pass to the exterior. See Walker et al (1996) Journal of Medical Entomology 33: 743 - 759.
This is the main cavity that fills with water and salts extracted from the hemolymph. These materials are passed to the coxaltubules for further processing and reabsorption of needed compounds.
In argasid ticks, the first of three lobes that extend from the posterolateral end of the ventral granular lobe of the maleaccessory gland. Absent in ixodid ticks.
adult male postero-lateral granular lobe 1
In argasid ticks, the second of three lobes that extend from the posterolateral end of the ventral granular lobe of the male accessory gland. Absent in ixodid ticks.
adult male postero-lateral granular lobe 2
In argasid ticks, the third of three lobes that extend from the posterolateral end of the ventral granular lobe of the maleaccessory gland. Absent in ixodid ticks.
adult male postero-lateral granular lobe 3
This is the cavity through which ingested blood flows to the midgut.
In ixodid ticks, a delicate membrane covers the preoral canal and separates it from the salivarium. This membrane is absent inargasid ticks where it is replaced by the hollow labrum.
Fig. 7-5, Fig. 7-6, in Biology of Ticks ISBN:0-19-505910-7.
Posteriorly project spines that occur on one or more of the four pairs of coxae. The number, length and shape of the coxalspines are useful characters for taxonomic classification of the species.
Narrow bifurcated duct that connects the acinus with the intralobular ducts. The acinar duct is surrounded by non-granular neckcells (=peritubular cells). At the center of the acinus is a small, narrow channel (lumen) communicating with the acinar duct. Evidently, the secretions from the granular cells pass initially into this narrow channel, then into the acinar duct for their passageout of the acinus into the intralobular duct and exit from the salivary glands.
The thin layer of cuticule that forms the inner lining of this duct.
adult salivary gland acinar duct lining.
The narrow channel of this duct that leads into the intralobular duct lumen.
The layer of squamous epithelial cells that forms the outer wall of the duct and secretes the cuticular lining.
adult salivary gland lobular duct epithelium
The relatively thick layer of cuticle lining the inner surface of the lobular duct.
adult salivary gland lobular duct cuticular lining.
The cavity of the lobular duct. Salivary secretions accumulate in the lumen of these ducts and pass into the main salivary ductfor exit to the salivarium.
A pair of small cells that surround the acinar duct. The constrictor cells control the outflow of secretions from the acinus into the main salivary duct. Constrictor cells are found only in type I (agranular) acini. However, it is possible that theperitubular cells (neck cells) in the granular acini perform a similar role.
adult salivary gland type I acinus constrictor cell
The main salivary duct is lined with a relatively thick, banded cuticular layer resembling the taenidium of the tracheae. The type I agranular acini are connected directly to the main salivary duct. Intralobular ducts connect at various locations to the main duct, transporting the secretions of the granular acini into the main duct.
The layer of epithelial cells surrounding the cutiuclar lining, forming the outer part of the wall of the salivary duct. These cells secrete the cuticular lining of the duct.
The cavity of the salivary duct. The lumina of the paired salivary ducts join to form the lumen of the salivarium. Salivary secretions from the acini of the salivary glands flow through the main salivary ducts into the salivarium and are expelled via thepreoral canal to the exterior.
The wall of the aorta is lined with a thin layer of squamous epithelium surrounded by layers of smooth muscle cells.
The cavity of the duct that conveys hemolymph anteriorly towards the periganglionic sinus.
This is the muscularized zone at the anteior end of the heart where the heart fuses with the aorta.
The thin membranous layer that surrounds the heart and encloses the pericardial sinus. The pericardial septum functions as a filtration membrane that filters the hemolymph before it enters the pericardial sinus.
The cavity of the heart containing filtered hemolymph that is circulated anteriorly and out into the aorta.
The fully mature capacitated (differentiated) sperm cells that are capable of migrating up the oviducts to the ovary and fertilizing the oocytes. Spermatozoa undergo capacitation within the endospermatophore within the body of the female (i.e., within the seminal receptacle. The fully mature spermatozoa may reach up to 1000 microns in some tick species .
The adult sensory system consists of the variety of sensory ogans, or sensilla, the detect chemical compounds (e.g., odors, taste), contact with objects or surfaces, light or shadows, temperature and humidty changes. They are classified by structure or function, or a combination of the two. For the purposes of this anatomical ontology, they will be characterized primarily by structureand secondarily by function. Examples include the setiform olfactosensilla in the Haller's organ, setiform mechanosensilla all over the body, capitulum and legs, thigmotactic sensilla in the integument, or the photosensilla in the eye. Many of these sensory organs are multifunctional, e.g., combined mechanochemosensory sensilla. Many sensilla are dispersed all over the body, capitulum and legs. Others are clustered in specialized organs such as the Haller's organ on the foreleg tarsi or the sensory field on the tip of the terminal segment of the palps (palpal article IV).
The hair-like body of the seta that extends from the setal socket in the cuticle. Often described as setiform sensilla, theshaft of the seta contains a fluid-filled cavity. The dendrite (s) of the adjacent sensory neuron (s) penetrate into the cavity of the shaft and may send minute branches to pores at the tip or along the margins. The shaft may have a solid cuticle (mechanosensory sensilla) or may have pores.
The photocreceptor neurons that detect light. These neurons are unusual, unipolar cells oriented in the dorso-ventral axis. Axons from these neurons join to form the optic nerve.
The layer of cells that surrounds and nourishes the retinal neurons in the eye.
In Amblyomm americanum, the pore canals in the lens are organized into bundles and oriented in the dorso-ventral axis. The pore bundles are believed to act as light or wave guides since the pore canals become progressively smaller and converge towards the interior, which is likely to intensify the incoming light.
The cavity of the malpighian tubules that contains numerous irridescent, spherical and subspherical guanine crystals of varying size.
Fig. 10-4, in Biology of Ticks ISBN:0-19-505910-7.
The peripheral nerve neurilemma is the amorphous, non-cellular layer that surrounds each nerve. The neurilemma extends into the body of the nerve to form mesaxons, an extension of the neurilemman that encloses individual axons or groups of axons within the body of the nerve. This is a unique feature of ticks.
The atrial muscles insert on the dorsal and ventral walls of the atrial chamber. They serve to dilate the atrial chamber whenthey contract.
Cavity surrounding the part of the esophagus that passes through the synganglion.
The large tracheal trunk that anastomoses into numerous small tracheae that envelope and supply the synganglion and its associated structures.
A neurosecretory tract (commissure) located in the dorsal region of the supraesophageal ganglion.
adult dorsal protocephalic neurosecretory tract
A rdige on the dorsal surface of the supraesophageal region of the synganglion.
adult periesophageal ridge/perineural association
A major commissure connecting different regions of the supreesophageal region of the synganglion.
adult ventral protocephalic neurosecretory tract
This neurosecretory tract is formed by axons primarily from the stomodeal neurosecretory tract.
A cluster a neuron cell bodies, presumably forming a neurosecretory center, adjacent to the ventral edge of the supraesophagealregion where the esophagus enters. Function unknown.
This is the chiasmatic neurosecretory pathway of pedal ganglion II (according to Wikipedia, a chiasma is a point where two or more nerves or nerve pathways cross).
The lateral neurosecretory tract (NST) extends between the supra- and sub-esophageal regions of the synganglion and connectsdifferent neurosecretory centers in both regions.
adult synganglion lateral neurosecretory tract
These neurosecretory tracts (NSTs) extend from the neurosecretory centers in the subesophageal region to the lateral-neurosecretory tract.
adult synganglion ventro-medial neurosecretory tract
One of the two types of epithelial cells that develop after blood feeding when the malpighian tubules are metabolically active in processing excretory wastes into guanine crystals. These differentiated cells are most prominent in the proximal regions of the malphighian tubules.
The primary cell type found in the lining epithelium of the malphighian tubules.
Fig. 10-7, in Biology of Ticks. ISBN:0-19-505910-7.
In the ovipositing female, these swollen areas are covered with innumerable ledges that lie medial to the horms of the gland. Numerous broad pits occur over these surfaces.
Fig. 17-EAA, Fig. 19-EAA, Fig. 20-EAA, Fig. 21-EAA, in Exp. Appl. Acarol. 25: 327-352.
adult Gene's organ balloon-like structure
The suspensory cord to which the retractor muscles of the gland attach.
During blood feeding, these enormously enlarged, fully differentiated digestive cells fill with hematin. They protrude as flask-shaped cells. Many detach from the basal lamina and float free in the lumen, eventually discharging their waste contents intothe cavity for elimination during defecation. In other cases, the enlarged, terminal end of the cell fragments and floats into thelumen. In some cases, the cells remain intact but the hematin-rich residual bodies that fill their cytoplasm are eliminated byexocytosis.
Fig. 9-24, in Biology of Ticks ISBN:0-19-505910-7.
Paired midgut diverticula that extend from the anterior diverticula towards the anterior end of the body.
adult midgut anterior median diverticula
Paired midgut diverticula that extend from the anterior diverticulum on each side and protrude laterally towards the anterior lateral margins of the body.
adult midgut anterior lateral diverticula
A small aciniform gland attached to the terminal end of the coxal tubule, near its junction with the coxal pore. Its function is unknown. It may serve as the source of the argasid sex pheromone.
Tip-pore sensilla located on the dorsal side of the terminal end of the tarsus at the junction with the tarsal apotele, These sensilla, which occur only in the males, were reported to recognize the female mounting sex pheromone.
Fig. 2-EAA_2, Fig. 3-EAA_2, in Exp. Appl. Acarol. 25: 327-352.
adult tarsal male claw sensilla dorsal pair
These are setiform (i.e., hair-like) sensilla in which the walls are covered by innumerable tiny submicroscopic pores. The pores are normally visible using the scanning or transmission electron microscope. These sensilla have a single wall. Setiform multiporose sensilla occur in the anterior pit of Haller's organ (Ap-1 sensillum or MD-1, MD-2 or MD-3 sensillum of various authors), in the Haller's organ capsule and in some cases distal to the Haller's organ. These sensilla have a well-established role asolfactory sensilla, detecting a wide range of odorants, e.g., NH3, CO2, 2,-dichlorophenol and many others.
adult multiporose single-walled sensilla
These are setiform (i.e., hair-like) sensilla in which the walls contain very pores in faint grooves along the margins. The pores are normally only visible using the scanning or transmission electron microscope. These sensilla have a double wall. Examples are found in the anterior pit and posterior capsule of the Haller's organ. These sensilla are believed to function as chemosensory sensilla, but their precise role is uncertain.
These are setiform sensilla that occur in the cluster of sensilla on the tip of palpal article IV, along the distal margins of tarsus I adjacent to the apotele, and possibly in the Haller's organ. They are believed to function as gustatory sensilla.
Setiform sensilla that lack any evidence of pores. These setae function as mechanosensory sensilla. No-pore setiform sensilla occur all over the body, legs and capitulum.
In a few species, a third multiporose setiform sensillum also occurs in the anterior pit of Haller's organ.
adult Haller's organ anterior pit MD-3 sensillum
These are tip pore sensilla similar to the dorsal pair. These sensilla occur only on tarsus I of the males and are situated adjacent to the base of the apotele. They are reported to detect the female mounting sex pheromone.
Fig. 2-EAA, in Exp. Appl. Acarol. 25: 327-352.
The two pits that occur on the inner cheliceral digits. Pit sensillum 1 (PS-1) is innervated by a single dendrite and isbelieved to function as a thermoreceptor. Pit sensillum 2 (PS-2) is innervated by 11 dendrites and is believed to function as a gustatory chemoreceptor.
Biological entity, which constitutes the structural organization of a biological organism, or is an attribute of thatorganization.
Material anatomical entity which has inherent 3D shape and is generated by coordinated expression of the organism's own genome.
Material anatomical entity in a gaseous, liquid, semisolid or solid state, with or without the admixture of cells and biologicalmacromolecules; produced by anatomical structures or derived from inhaled and ingested substances that have been modified byanatomical structures as they pass through the body.
Non-material anatomical entity of three dimensions, which is generated by morphogenetic or other physiologic processes; issurrounded by one or more anatomical structures; contains one or more organism substances or anatomical structures.
Physical anatomical entity which is a three-dimensional space, surface, line or point associated with a material physicalanatomical entity.
Non-material anatomical entity of one dimension, which forms a boundary of an anatomical surface or is a modulation of ananatomical surface.
Non-material anatomical entity of zero dimension, which forms a boundary of an anatomical line or surface.
Non-material anatomical entity of two dimensions, that is demarcated by anatomical lines or points on the external or internal surfaces of anatomical structures.
Anatomical group that is has as its parts distinct anatomical structures interconnected by anatomical structures at a lowerlevel of granularity.
Anatomical structure that is an individual member of a species and consists of more than one cell.
Anatomical structure which has as its direct parts a maximally connected cell compartment surrounded by a plasma membrane.
Anatomical structure which is a direct part of the cell.
Multi-tissue structure that is part of a compound organ.
Multi-tissue structure that is not part of a compound organ.
Anatomical structure that has as its parts two or more multi-tissue structures of at least two different types and which throughspecific morphogenetic processes forms a single distinct structural unit demarcated by bona fide boundaries from other distinctanatomical structures of different types.
Gonochoristic organism that can produce male gametes.
Gonochoristic organism that can produce female gametes.
Multi-cellular organism that can produce both male and female gametes.
Multi-cellular organism that does not produce gametes.
Anatomical structure which is a primary subdivision of whole organism. The mereological sum of these is the whole organism.
Anatomical structure that consists of cell parts and cell substances and together does not constitute a cell or a tissue.
Anatomical group that has its parts adjacent to one another.
Anatomical structure that is contiguous with the embryo and is comprised of portions of tissue or cells that will not contributeto the embryo.
Anatomical structure, which consists of similar cells and intercellular matrix, aggregated according to genetically determinedspatial relationships.
Hermaphroditic organism that produces gametes first of one sex, and then later of the other sex.
Hermaphroditic organism that produces both male and female gametes at the same time.
Multi-cellular organism that has male and female sexes.
Sequential hermaphroditic organism that produces gametes first of the male sex, and then later of the female sex.
Sequential hermaphroditic organism that produces gametes first of the female sex, and then later of the male sex.
Anatomical structure consisting of at least two non-overlapping organs, multi-tissue aggregates or portion of tissues or cellsof different types that does not constitute an organism, organ, multi-tissue aggregate, or portion of tissue.
Anatomical structure that has as its parts two or more portions of tissue of at least two different types and which throughspecific morphogenetic processes forms a single distinct structural unit demarcated by bona-fide boundaries from other distinctstructural units of different types.
Anatomical space that is part of a cell.
Portion of organism substance located within a cell.
Cell that is an individual member of a species.
Acellular anatomical structure that consists of a thin sheet of fibrous proteins that underlie and support the cells of anepithelium. It separates the cells of an epithelium from any underlying tissue.
Portion of tissue, that consists of one or more layers of epithelial cells connected to each other by cell junctions and whichis underlain by a basal lamina.
Unilaminar epithelium that consists of a single layer of cuboidal cells.
Unilaminar epithelium that consists of a single layer of columnar cells.
Epithelium that consists of more than one layer of epithelial cells.
Unilaminar epithelium that consists of a single layer of squamous cells.
Epithelium that consists of epithelial cells not arranged in one ore more layers.
Compound organ that contains one or more macroscopic anatomical spaces.
Epithelium that consists of a single layer of epithelial cells.
Compound organ that does not contain macroscopic anatomical spaces.
Cell which has as its part a cytoskeleton that allows for tight cell to cell contact and which has apical-basal cell polarity.