ATI RN
Immune System NCLEX Questions Quizlet Questions
Question 1 of 5
How do cytotoxic T cells (CTLs) kill infected cells?
Correct Answer: C
Rationale: CTLs use perforin, granzyme B, and FasL to trigger apoptosis ; antibodies are B-cell products, cytokines are secondary.
Question 2 of 5
When macrophages in a tissue encounter bacteria, they release cytokines that induce an inflammatory response. These cytokines act on other immune cells, to recruit them to the site of infection and to enhance their activities. In addition, these cytokines act on the endothelial cells of the blood vessel wall to:
Correct Answer: A
Rationale: Cytokines increase endothelial permeability for immune cell extravasation; tightening junctions , proliferation , or microbicidal action aren't primary effects.
Question 3 of 5
Even when the complement cascade fails to proceed beyond generating the C3 convertase, complement activation is effective at inducing pathogen uptake and destruction. This process of immune protection is mediated by:
Correct Answer: C
Rationale: C3b and fragments (iC3b) engage phagocyte complement receptors for uptake ; not inhibitory , proteases , or B cells .
Question 4 of 5
Recombination signal sequences are conserved heptamer and nonamer sequences that flank the V, J, and D gene segments which undergo recombination to generate the final V region coding exon. Some of these have 12-nucleotide spacers between the heptamer and nonamer, and others have 23-nucleotide spacers. The reason recombination signal sequences come in these two forms is:
Correct Answer: A
Rationale: 12/23 rule ensures V-D-J assembly ; not helix face , locus specificity , or non-Ig genes .
Question 5 of 5
The reason for naming the closed circulatory systems
Correct Answer: C
Rationale: Closed circulatory systems are named so because blood remains confined within vessels, unlike open systems where it bathes tissues directly.