How does a tick feed on blood? - briefly
A tick penetrates the host’s skin with its barbed hypostome, releases saliva containing anticoagulants, and draws blood through a flexible feeding tube into its midgut. The ingested blood is stored in the expanding gut until the tick detaches.
How does a tick feed on blood? - in detail
Ticks attach to a host using their fore‑legs, which locate a suitable site through sensory organs that detect heat, carbon dioxide, and movement. Once positioned, the tick inserts its barbed mouthparts, called the hypostome, into the skin. The hypostome’s backward‑pointing teeth anchor the parasite, preventing it from being dislodged.
Salivary glands secrete a complex cocktail of bioactive substances into the wound. These include:
- Anticoagulants that inhibit clot formation, ensuring a continuous flow of plasma.
- Vasodilators that expand local blood vessels, increasing blood availability.
- Immunomodulators that suppress the host’s inflammatory response and reduce pain perception.
A proteinaceous cement cone, produced by the tick’s salivary glands, hardens around the hypostome, creating a stable attachment. The tick then draws blood through a dorsal feeding tube that connects the host’s capillaries to the tick’s gut. Blood is stored in the midgut, where it is diluted with water and electrolytes to prevent osmotic shock.
Engorgement proceeds in phases:
- Initiation (0–24 h): Minimal blood intake; saliva compounds dominate to establish a feeding site.
- Rapid expansion (24–72 h): Blood intake accelerates; the tick’s body swells up to several times its unfed weight.
- Termination (72–96 h): Feeding ceases, the cement cone hardens fully, and the tick detaches, leaving the wound sealed.
During the feeding period, pathogens present in the host’s blood can be transmitted through the saliva. The tick’s fore‑gut, which remains free of host blood, prevents immediate backflow of pathogens, reducing the risk of self‑infection.
After detachment, the tick digests the ingested blood over several days, converting proteins into amino acids and storing excess nutrients for egg production in females. The entire process combines mechanical anchoring, biochemical manipulation of host physiology, and efficient nutrient acquisition to sustain the parasite’s life cycle.