4. Order the following events (1 through 8, with 1 being the first and 8 being t

Question

4. Order the following events (1 through 8, with 1 being the first and 8 being the last) as they would occur during an infection. (8 pts) Effector T cells enter site of infection Leukocytes begin to extravasate across the activated endothelium Tumor Necrosis Factor-a levels rise at the site of infection Pathogen penetrates epithelium Cytokines stimulate fatty acids to be released from adipose tissue Infection is cleared Activated T/B lymphocytes differentiate in draining lymph node Ficolins bind to pathogen membrane

Explanation / Answer

Upon infection, Pathogen penetrates epithelium and rapidly divides. These rapidly dividing cells then activates compliment (e.g. Ficolins) which then binds to pathogen membrane. The fragment of Compliment like C3a, C5a recruits neutrophils and activate local mast cells which increase blood flow. These activated local immune cells release cytokines (e.g. TNF alpha) therefore, cytokines level rise at the site of infection. This rise in the level of cytokines stimulates fatty acid to be released from adipose tissue causing the activation of endothelium. In the next event, leukocytes begin to extravasate across the activated endothelium. they cause the phagocytosis of the pathogen and also they represent the antigen in the lumph node to activate T/B lymphocytes. Activated T/B lymphocytes then differentiate into memory and effector cells in the lymph node and effector cells are releases in blood steam. Effector T cells then enter at the site of infection and cleared the infection.   

Related Questions

Navigate

• Browse (All)
• Browse 4
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.