Which part of the antibody determines its physiological effects?

Correct Answer: B

Rationale: The correct answer is B: Fc fragment. The Fc fragment of an antibody determines its physiological effects by interacting with immune cells and other effector molecules. It mediates processes like opsonization, complement activation, and antibody-dependent cell-mediated cytotoxicity. The Fab fragment (A) contains the antigen-binding site but does not directly influence physiological effects. The variable region (C) is part of both the Fab and Fc portions and contributes to antigen specificity but does not solely determine physiological effects. The antigen-binding site (D) is located within the Fab portion and is responsible for binding to specific antigens, not for exerting physiological effects.

Correct Answer: B

Rationale: The correct answer is B, Grave's disease, for Type V hypersensitivity. In Type V hypersensitivity, antibodies target cell surface receptors, leading to abnormal stimulation or blockage. In Grave's disease, antibodies target the thyroid-stimulating hormone receptor, leading to excessive thyroid hormone production. Multiple sclerosis (A) is an example of Type IV hypersensitivity involving T cell-mediated response. Rheumatoid arthritis (C) is an example of Type III hypersensitivity involving immune complex deposition. Type 1 diabetes mellitus (D) is an example of Type II hypersensitivity involving antibody-mediated destruction of cells.

Correct Answer: D

Rationale: The correct answer is D: T cell apoptosis. Anaphylaxis is a severe allergic reaction that involves a rapid immune response. T cell apoptosis is not a typical symptom of anaphylaxis. Rationale: 1. A: Sudden drop in blood pressure is associated with anaphylaxis due to systemic vasodilation. 2. B: Massive edema is common in anaphylaxis due to increased vascular permeability. 3. C: Severe bronchoconstriction is a hallmark of anaphylaxis, leading to respiratory distress. 4. D: T cell apoptosis is not a characteristic feature of anaphylaxis. T cells play a role in adaptive immunity, not the immediate hypersensitivity reaction seen in anaphylaxis. Summary: T cell apoptosis is not typically associated with anaphylaxis, unlike the other symptoms listed which are common manifestations of this severe allergic reaction.

Correct Answer: B

Rationale: The primary effector cell in delayed-type hypersensitivity is T cells. T cells play a crucial role in initiating and orchestrating the immune response in delayed hypersensitivity reactions. Upon exposure to the antigen, T cells are activated and release cytokines that recruit and activate macrophages, leading to the inflammatory response characteristic of delayed-type hypersensitivity. Mast cells are involved in immediate hypersensitivity reactions mediated by IgE. Neutrophils are primarily involved in acute inflammation and combating bacterial infections. B cells are responsible for antibody production in humoral immunity, not in delayed hypersensitivity reactions. Therefore, the correct answer is B: T cells.

Correct Answer: D

Rationale: The correct answer is D because abruptly stopping prednisone can lead to adrenal insufficiency due to suppression of the body's natural cortisol production. Adrenal insufficiency can be life-threatening. Priority is given to this information to ensure the client's safety. Choice A is incorrect as jitteriness or nervousness are common side effects but not the priority. Choice B is incorrect as sodium and fluid retention are potential side effects but not as critical as avoiding adrenal insufficiency. Choice C is incorrect as fat redistribution is a long-term effect but not as immediate as the risk of adrenal insufficiency.