How does a tick penetrate skin? - briefly
Ticks insert their chelicerae to cut the epidermis, then extend a barbed hypostome that anchors into the dermis while secreting anticoagulants to facilitate blood flow. The mouthparts remain embedded until the tick detaches after feeding.
How does a tick penetrate skin? - in detail
Ticks attach to a host by inserting a specialized set of mouthparts called the capitulum. The capitulum consists of chelicerae, a hypostome, and palps. Chelicerae act as cutting tools, slicing the epidermis and dermis to create a small entry wound. The hypostome, a barbed structure covered with backward‑facing teeth, slides into the wound and anchors the tick firmly. Palps guide the hypostome toward deeper tissue layers.
During insertion, the tick releases saliva containing anticoagulants, vasodilators, and immunomodulatory proteins. These substances prevent blood clotting, expand local blood vessels, and suppress host immune responses, facilitating prolonged feeding. Saliva also contains cement proteins that harden around the mouthparts, reinforcing attachment and sealing the feeding site.
The feeding apparatus creates a channel, termed the feeding tube, that connects the hypostome to the tick’s foregut. Blood flows through this tube into the tick’s digestive system. The tick can remain attached for several days, expanding the feeding cavity as it engorges.
Detachment occurs when the tick secretes enzymes that dissolve the cement matrix. The mouthparts withdraw, leaving only a small puncture that typically heals within hours.
Key steps in the penetration process:
- Cheliceral incision of the skin surface
- Advancement of the hypostome into dermal tissue
- Salivary injection of anticoagulant and immunosuppressive agents
- Formation of cemented seal around the mouthparts
- Continuous blood uptake through the feeding tube
- Enzymatic dissolution of cement and removal of mouthparts