An older client asks the nurse why 'people my age' have weaker immune systems than younger people. What responses by the nurse are best? (Select all that apply.)

Correct Answer: C

Rationale: The correct answer is C: 'You have lower levels of plasma proteins in the blood.' As we age, there is a decline in the production of plasma proteins, which play a crucial role in immune function. These proteins help fight infections and regulate immune responses. Lower levels can weaken the immune system's ability to respond effectively to pathogens. Choice A is incorrect because while bone marrow does produce blood cells, it does not directly relate to the weakening of the immune system with age. Choice B is incorrect as decreased platelet levels primarily affect blood clotting, not immune function. Choice D is incorrect because lymphocytes becoming more reactive to antigens is not a characteristic of aging immune systems.

Correct Answer: C

Rationale: The correct answer is C: Rhodnius prolixus. This parasite is responsible for causing Chagas disease. The initial symptoms of unilateral palpebral edema and ipsilateral lymphadenopathy are characteristic of the acute phase of Chagas disease. The development of megaesophagus and megacolon are complications seen in the chronic phase. Rhodnius prolixus is a vector for Trypanosoma cruzi, the parasite that causes Chagas disease. Glossina morsitans is the vector for African trypanosomiasis (sleeping sickness), Ixodes scapularis is the vector for Lyme disease, and Simulium damnosum is the vector for onchocerciasis (river blindness), making them incorrect choices for this particular parasitic infection.

Correct Answer: D

Rationale: Rationale for Choice D (Lymphocyte predominance): 1. Reed-Sternberg cells are infrequent or absent in lymphocyte predominance Hodgkin's lymphoma. 2. 'Popcorn cells' are seen in lymphocyte predominance Hodgkin's lymphoma. 3. Predominance of benign lymphocytes in the background is characteristic of lymphocyte predominance Hodgkin's lymphoma. Summary of other choices: A: Nodular sclerosis - Characterized by collagen bands dividing lymph node into nodules, not 'popcorn cells'. B: Mixed cellularity - Reed-Sternberg cells present, not 'popcorn cells'. C: Lymphocyte depleted - Few to no lymphocytes seen, not benign lymphocytes as described in the question.

Correct Answer: B

Rationale: The correct answer is B: Vitamin B12 deficiency. As a strict vegetarian who does not consume any meat, fish, or milk products, Mr XY is at risk for Vitamin B12 deficiency. Vitamin B12 is primarily found in animal products and is essential for red blood cell production. Anemia can result from Vitamin B12 deficiency, leading to symptoms such as fatigue and weakness. Iron deficiency (A) is also common in vegetarians, but in this case, the focus is on Vitamin B12 due to the exclusion of all animal products. Defects in erythropoietin production (C) are not related to Mr XY's dietary choices. Calcium-deficiency (D) is not directly related to anemia in this scenario.

Correct Answer: B

Rationale: Rationale: 1. Bone marrow increases erythropoiesis in response to iron therapy. 2. Reticulocytes are immature red blood cells derived from erythroblasts, indicating active erythropoiesis. 3. Myelocytes are precursors of granulocytes, not involved in erythropoiesis. 4. Ring sideroblasts are abnormal erythroblasts with iron granules, not indicative of active erythropoiesis. 5. Target cells are red blood cells with central "target-like" appearance due to excess membrane, not directly related to erythropoiesis.