What person is at risk for hypercalcemia?

Choice A reason: Poison ivy causes a type IV (cell-mediated) hypersensitivity reaction, where T-cells react to urushiol, triggering a delayed inflammatory response. This leads to dermatitis with itching and rash, making this the correct choice.

Choice B reason: Allergic hypersensitivity is a broad term, often referring to type I (IgE-mediated) reactions, like anaphylaxis. Poison ivy involves T-cell-mediated delayed hypersensitivity, not immediate allergic responses, making this choice incorrect.

Choice C reason: Immune complex hypersensitivity (type III) involves antigen-antibody complexes causing tissue damage, as in lupus. Poison ivy reactions are T-cell-driven, not immune complex-mediated, making this choice incorrect for the reaction.

Choice D reason: Cytotoxic hypersensitivity (type II) involves antibodies attacking cell surface antigens, as in hemolytic anemia. Poison ivy causes a T-cell-mediated skin reaction, not antibody-driven cytotoxicity, making this choice incorrect.

Choice A reason: Overinflated alveoli and air trapping occur in emphysema or COPD, not atelectasis. Atelectasis involves alveolar collapse, reducing lung volume and gas exchange, not overinflation, making this choice incorrect for the pathophysiology of atelectasis.

Choice B reason: Atelectasis is the collapse of alveoli, often due to obstruction, compression, or surfactant deficiency, impairing ventilation and perfusion. This reduces gas exchange, causing hypoxia, and matches the pathophysiological process, making this the correct choice for atelectasis.

Choice C reason: Inflammation of the bronchi (bronchitis) involves airway inflammation, not alveolar collapse. Atelectasis results from physical collapse of alveoli, not primarily inflammatory processes, making this choice incorrect for atelectasis’s pathophysiology.

Choice D reason: Inflammatory congestion in alveoli describes pneumonia or pulmonary edema, not atelectasis. Atelectasis involves alveolar collapse, reducing ventilation without primary inflammation or fluid accumulation, making this choice incorrect for the described process.