What does a tick do inside the body? - briefly
After attaching to the host, a tick inserts its hypostome, releases anticoagulant saliva, and consumes blood while possibly transmitting pathogens. Extended feeding can cause local tissue damage and trigger systemic infection.
What does a tick do inside the body? - in detail
Ticks attach to the skin, pierce the epidermis with their hypostome, and create a secure channel for blood intake. During attachment they inject saliva that contains a complex mixture of biologically active molecules. Anticoagulants such as apyrase and tick‑derived anticoagulant peptide prevent clot formation, allowing continuous flow of blood into the feeding cavity. Immunomodulatory proteins suppress local immune detection, while anti‑inflammatory agents reduce pain and swelling, facilitating prolonged feeding.
The feeding process proceeds in three stages. First, the tick inserts its mouthparts and begins salivation; the host’s immediate response is limited by the pharmacologically active saliva. Second, the insect expands its body as it ingests large volumes of blood, storing the fluid in the mid‑gut where it is digested slowly. Enzymes break down proteins and lipids, providing nutrients for development and reproduction. Third, after the blood meal is complete, the tick disengages and drops off the host, often within 24–48 hours.
Pathogen transmission occurs primarily during the salivation phase. When the tick’s salivary glands release infectious agents, they are deposited directly into the host’s bloodstream. Commonly transmitted organisms include:
- Borrelia burgdorferi (Lyme disease bacterium)
- Rickettsia spp. (spotted fever agents)
- Anaplasma phagocytophilum (human granulocytic anaplasmosis)
- Babesia microti (protozoan causing babesiosis)
- Powassan virus (flavivirus)
These microbes exploit the tick’s saliva to evade host defenses, establishing infection before the immune system can mount an effective response. The host may experience localized erythema at the bite site, followed by systemic symptoms such as fever, fatigue, joint pain, or neurologic signs, depending on the pathogen involved.
Internally, the tick’s mid‑gut epithelium serves as a reservoir for ingested pathogens. After blood digestion, some organisms migrate to the salivary glands, positioning themselves for subsequent transmission during the next feeding cycle. The tick’s own immune mechanisms, including antimicrobial peptides, regulate microbial load but often coexist with the pathogens that have adapted to the tick environment.
In summary, the parasite’s activity inside a vertebrate host involves mechanical attachment, pharmacologically mediated blood acquisition, nutrient processing, and the delivery of disease‑causing agents. The interplay of saliva components, host immune modulation, and pathogen survival strategies defines the clinical consequences of a bite.