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Tick Morphology (view source)

Revision as of 15:01, 7 July 2010

442 bytes removed , 15:01, 7 July 2010

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There are 3 major constituents of the mouthparts of ticks; palps, chelicerae and the hypostome. The palps are sensory organs on protuding on either side of the capitulum, they are used to locate a suitable site for feeding. Once a suitable feeding site has been located the sharp chelicerae are used to create a puncture wound in the skin of the host. The hypostome is then pushed through the wound into the host, where it attaches using backwards facing teeth. A dorsal groove on the hypostome allows the downward flow of tick saliva into the host as well as the upward flow of host blood during tick feeding.

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==Feeding==

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===Feeding===

[[Image:Engorged Ixodes scapularis.jpg|thumb|right|150px|Engorged ''Ixodes scapularis'' - Thomas Hedden]]

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All of the above mechanisms enable the tick to effectively and succesfully counter the hosts defenses and feed successfully.

During feeding excess water is passed back into the host via the hypostome as the tick is unable to remove water via its cuticle, this allows greater intake of blood from the host.

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*Tick saliva flows into host and contains

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**Histamine blocking agents to minimise the host inflammatory response

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**Anticoagulants to ensure the free flow of blood

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**Cytolysins to enlarge the feeding lesion

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**Vasoactive mediators, enterases and carbohydrate splitting enzymes to increase the vascular permeability, facilitating feeding

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**Paralytic toxins

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*Host tissue is broken down leaving a zone of necrosis creating a '''feeding lesion'''

[[Category:Ticks]]

[[Category:To_Do_-_NickJ]]

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