ATI RN
Immune System NCLEX Questions Questions
Question 1 of 5
Which of the following is NOT a chemical barrier that prevents infection?
Correct Answer: B
Rationale: Mucous membranes are physical, not chemical barriers.
Question 2 of 5
Cytotoxic T cells can be activated via which of the following?
Correct Answer: C
Rationale: Cytotoxic T cells (CD8+) are activated by viral peptides on MHC-I.
Question 3 of 5
An example of secondary mediators released by Mast cells would be
Correct Answer: B
Rationale: PAF is a secondary mediator; histamine , heparin , and chymase are primary.
Question 4 of 5
Lysis of cells by complement is finalized by the formation of:
Correct Answer: C
Rationale: Membrane Attack Complex lyses cells; C1q starts classical, immune complexes trigger, and properdin stabilizes alternative.
Question 5 of 5
In activated T cells, CD152 (CTLA4) is expressed on the cell surface and inhibits the binding of CD28 on these same T cells to:
Correct Answer: D
Rationale: CTLA4 blocks CD28-B7 (CD80/86); not IL-2 , CD4 , CD8 , or CD95 .