ATI RN
Lymphatic System Exam Questions Questions
Question 1 of 5
Which cells in the thymus are responsible for expressing tissue-specific antigens through the action of AIRE?
Correct Answer: A
Rationale: Medullary thymic epithelial cells express tissue-specific antigens via AIRE for negative selection.
Question 2 of 5
Naive B and T lymphocytes are small, quiescent cells with little cytoplasm and low metabolic activity. Yet within hours after being activated following encounter with their antigen, these cells enlarge and up-regulate many biosynthetic and metabolic pathways. Approximately one day later, the cells begin dividing, and for several days they are the most rapidly dividing cells in the body, undergoing 2-4 rounds of cell division every day. In order to maintain this phenomenal rate of cell division, lymphoblasts must:
Correct Answer: C
Rationale: Lymphoblasts up-regulate glycolysis via glucose transporters/enzymes ; naive cells lack stores , don't engulf lymphocytes , or phagocytose broadly .
Question 3 of 5
Immunodeficiency diseases occur when individuals have defects in leukocyte adhesion to inflamed endothelial cells, thereby impeding the extravasation of phagocytes into infected tissues. When neutrophils from one class of these patients were isolated and tested using in vitro assays for neutrophil-endothelial cell interactions and extravasation, it was found that the neutrophils could slowly roll along the endothelial vessel wall but were unable to arrest and migrate across the endothelium. The most likely protein deficient in these neutrophils is:
Correct Answer: D
Rationale: Integrins mediate neutrophil arrest; rolling (selectins, B/C) occurs, but without integrins, migration fails; ICAMs are on endothelium.
Question 4 of 5
The adaptive immune system uses multiple strategies to generate diversity in our ability to mount responses to a wide array of infectious microorganisms. These strategies include the generation of diverse repertoires of B-cell and T-cell antigen receptors, as well as polymorphism of MHC genes. The polymorphism of MHC genes differs from the diversity of lymphocyte antigen receptors in that:
Correct Answer: D
Rationale: MHC polymorphism varies between individuals ; receptor diversity is clonal within one (A, B, C are incorrect).
Question 5 of 5
The way in which some organism supplies some other organism with food and energy known as
Correct Answer: A
Rationale: Food chains describe the linear transfer of energy and nutrients from one organism to another in an ecosystem.