ATI RN
Chapter 20 The Lymphatic System and Immunity Sample Questions Questions
Question 1 of 5
What is the role of NK cells in the innate immune system?
Correct Answer: B
Rationale: NK cells kill virus-infected and cancer cells ; they produce cytokines but aren't phagocytic or pain-related .
Question 2 of 5
Which cell has the shortest lifespan?
Correct Answer: D
Rationale: Neutrophils have the shortest lifespan (hours, D); plasma B cells (A, B) and DCs live longer.
Question 3 of 5
What traits characterize antigens?
Correct Answer: A
Rationale: Antigens are diverse molecules (proteins, polysaccharides, etc.) triggering immunity ; not only microbial , not antibodies , not just proteins .
Question 4 of 5
The pattern recognition receptors on cells of the innate immune system are genetically encoded, meaning that their sequences and specificities are determined prior to the development of the individual. In contrast, the antigen receptors of B and T lymphocytes arise from a random rearrangement process that occurs differently in each lymphocyte as it develops. One potential problem entailed by the random process that generates lymphocyte antigen receptors is the possibility that:
Correct Answer: D
Rationale: Random rearrangement risks non-functional receptors ; self-recognition is managed by tolerance, non-specificity or graft rejection are secondary.
Question 5 of 5
Many of the inflammatory mediators produced by tissue macrophages at sites of infection act on the endothelial cells lining the blood vessel walls. An exception to this is (are) the:
Correct Answer: D
Rationale: Bradykinin causes pain, not endothelial effects; cytokines (A, C), chemokines , and TNF target endothelium.