Your patient is a child who has no detectable T or B cells. This immunodeficiency is most probably the result of a defect in

Correct Answer: D

Rationale: The correct answer is D because T and B cells originate from hematopoietic stem cells in the bone marrow. If the patient has no detectable T or B cells, it indicates a defect in the stem cells originating in the bone marrow. A: The thymus is responsible for T cell maturation, not their origin. B: The bursal equivalent is specific to birds and not relevant in humans. C: T cell-B cell interaction occurs after the maturation of T and B cells, so a defect in this interaction would not lead to the absence of both cell types.

Correct Answer: A

Rationale: The correct answer is A: antigens. Antigens are molecules that can trigger an immune response in the body. Certain microbes, foreign tissues, and cancerous cells all contain antigens that are recognized as foreign by the immune system, leading to an immune response. Choice B: enzymes, Choice C: fats, and Choice D: cytoplasm do not have the ability to trigger immune responses like antigens do. Enzymes are proteins that catalyze biochemical reactions, fats are molecules used for energy storage, and cytoplasm is a component of cells but none of them are recognized by the immune system as foreign invaders.

Correct Answer: B

Rationale: The correct answer is B: Increased mucus secretion- histamine release; neurotransmitter the body produces during an allergic reaction. Histamine release during an allergic reaction triggers the production of mucus to protect the airways from allergens. This increased mucus secretion helps to expel the allergen and reduce inflammation in the airways. Choices A, C, and D are incorrect because histamine does not cause bronchial dilation (A), decreased heart rate (C), or skin dryness and flaking (D) during an allergic reaction.

Correct Answer: B

Rationale: The correct answer is B because erythema at the incision site is an early sign of a wound infection. It indicates inflammation and possible bacterial presence, necessitating nurse intervention. WBC count within range (choice A) does not necessarily rule out infection. Clear drainage (choice C) may not always indicate infection, and reduced pain (choice D) can be subjective and not a reliable indicator of infection. Erythema is a specific indicator that warrants immediate attention to prevent further complications.

Correct Answer: B

Rationale: The correct answer is B because taking naproxen with aspirin can increase the risk of bleeding and gastrointestinal ulceration due to their similar mechanisms of action. Mixing NSAIDs like naproxen with aspirin can lead to serious side effects. Choice A is incorrect because crushing naproxen can affect its effectiveness and should not be done without consulting a healthcare provider. Choice C is incorrect as taking naproxen with food may help reduce stomach upset but it is not a requirement. Choice D is incorrect because black stools are a potential side effect of naproxen and should be reported, but it is not the most important concern in this scenario.