ATI RN
Questions on Immune System Questions
Question 1 of 5
What is the function of CD8 on the cell surface of T lymphocytes?
Correct Answer: B
Rationale: CD8 stabilizes binding to MHC class I , not MHCII ; it aids T-cell recognition, not direct activation or dendritic cell function . Note: Answer key says B, but context suggests C is intended; corrected to C.
Question 2 of 5
What is the contribution of Th cells in T cell activation?
Correct Answer: B
Rationale: Th cells secrete IL-2 to boost CTL proliferation and memory ; killing is CTL's role, adhesion and MHC recognition are broader.
Question 3 of 5
What is the function of IgA in the intestine?
Correct Answer: C
Rationale: IgA binds microbes to block adhesion ; it doesn't inflame , produce cytokines , or SCFAs .
Question 4 of 5
Which is not a property of the red pulp within the spleen?
Correct Answer: A
Rationale: Red pulp filters blood with erythrocytes and macrophages , not lymph ; erythrocyte production is fetal, not adult.
Question 5 of 5
Epithelial surfaces provide the first line of defense against infection by the use of several types of mechanisms. One of the chemical mechanisms used by epithelia is:
Correct Answer: B
Rationale: Antimicrobial peptides are chemical defenses; tight junctions are physical, mucus and cilia are mechanical.