One of the first cells to respond to the presence of a bacterium is called a mac
ID: 280913 • Letter: O
Question
One of the first cells to respond to the presence of a bacterium is called a macrophage. Macrophages detect bacteria through a number of receptors, triggering signaling pathways that lead to the secretion cytokines, including TNF? and interleukin 8 (IL-8). TNF? is the ligand for a receptor on blood endothelial cells (which line blood vessels), and induces these cells to produce additional IL-8. IL-8 secretion leads to the recruitment of cells called neutrophils from the blood into the tissue, which can also secrete inflammatory cytokines like TNF? in response to microbial products. Both neutrophils and macrophages are capable of phagocytosing bacteria and destroying them in lysosomes.
Which of the following is an example of negative feedback in the inflammatory pathway described above?
migration of neutrophils into inflamed tissue
phagocytosis of bacteria by neutrophils
secretion of TNF? by macrophages
secretion of IL-8 by neutrophils
Explanation / Answer
Secretion of TNF alpha by macrophages is the negative feedback in the above inflammatory pathway.
Related Questions
drjack9650@gmail.com
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.