ATI RN
Chapter 20 The Lymphatic System and Immunity Sample Questions Questions
Question 1 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 2 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 3 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.
Question 4 of 5
IgM is the first antibody isotype secreted following activation of a naive B cell. IgM is found at high concentrations in the serum, and is found as a very high molecular weight complex. This high molecular weight complex is composed of:
Correct Answer: D
Rationale: IgM forms a pentamer for high avidity; not mixed isotypes , non-Ig proteins , or complement .
Question 5 of 5
Peripheral nervous system (PNS)
Correct Answer: D
Rationale: The PNS is outside the CNS (brain and spinal cord) and includes nerves and ganglia, making A and B correct.