Patient with weakness, tingling, macrocytic anemia. Not a factor?

Correct Answer: A

Rationale: The correct answer is A: Chronic atrophic gastritis. This condition leads to vitamin B12 deficiency, causing macrocytic anemia, weakness, and tingling. Chronic atrophic gastritis affects the stomach's ability to produce intrinsic factor needed for B12 absorption. Ileal resection impairs B12 absorption, tapeworm infestation competes for B12, and alcoholism can lead to poor diet and malabsorption, all contributing to macrocytic anemia.

Correct Answer: B

Rationale: The correct answer is B: Reticulocytes. Reticulocytes are immature red blood cells released by the bone marrow into the bloodstream during erythropoiesis. They still contain remnants of ribosomal RNA, giving them a reticulated appearance under a microscope. Myelocytes (A) are immature white blood cells, not involved in erythropoiesis. Ring sideroblasts (C) are found in the bone marrow in certain types of anemia, not a direct sign of erythropoiesis. Target cells (D) are red blood cells with a target-like appearance due to excess membrane, not specific to erythropoiesis.

Correct Answer: C

Rationale: The correct answer is C: Binding antithrombin III. Heparin enhances the activity of antithrombin III, which in turn inhibits several clotting factors, specifically thrombin and factor Xa. This prevents the formation of fibrin clots. Choices A, B, and D are incorrect because heparin does not inhibit vitamin K factors, prevent platelet activation, or activate tissue plasminogen activator (tPA) directly. Heparin works primarily by enhancing the inhibitory action of antithrombin III on clotting factors.

Correct Answer: D

Rationale: The correct answer is D: Allograft. An allograft is a graft between members of the same species but with different genetic makeup (not identical twins). This answer is correct because allografts involve transplanting tissues or organs from one individual to another within the same species. Autograft (A) is a graft from one part of the body to another in the same individual. Isograft (B) is a graft between identical twins. Xenograft (C) is a graft between different species. In this context, allograft is the most appropriate term for graft between members of the same species with different genetic makeup.

Correct Answer: D

Rationale: The correct answer is D because polycythemia is a compensatory mechanism in response to tissue hypoxia in clients with COPD. As the lungs are unable to efficiently oxygenate the blood due to the lung disease, the body produces more red blood cells to increase oxygen-carrying capacity and compensate for the decreased oxygen levels. Choices A and C are incorrect because they do not directly address the underlying cause of polycythemia in COPD. Choice B is incorrect as overactive bone marrow is not the primary reason for polycythemia in COPD.