Which of the following alters the function of thrombin from a procoagulant protein to one that downregulates the formation of fibrinogen?

Correct Answer: D

Rationale: The correct answer is D: Thrombomodulin. Thrombomodulin binds to thrombin and changes its function from procoagulant to anticoagulant by activating protein C. This leads to the downregulation of fibrinogen formation. Protein C (choice A) and its cofactor Protein S (choice B) are involved in the anticoagulant pathway but do not directly alter thrombin's function. Antithrombin (choice C) inhibits thrombin and other coagulation factors, but it doesn't specifically change thrombin's function from procoagulant to anticoagulant.

Correct Answer: D

Rationale: The correct answer is D: Transmembrane iron exporter. Ferroportin is a transmembrane protein that functions as an iron exporter, allowing iron to move out of cells. This is crucial in iron metabolism as it facilitates the release of iron from cells into the bloodstream for transport to other tissues. A: A form of storage iron in intestinal mucosal cells - This is incorrect as ferroportin is not involved in storing iron in cells. B: A transport protein in the plasma - This is incorrect as ferroportin is not primarily a plasma protein but rather a transmembrane protein. C: A receptor protein on the surface of erythroid progenitors - This is incorrect as ferroportin is not a receptor protein but an exporter protein.

Correct Answer: A

Rationale: The correct answer is A: Extremity. Rhabdomyosarcoma in extremities has a worse prognosis due to difficulties in achieving complete surgical resection and higher risk of metastasis. Extremity tumors are often larger and more challenging to remove completely, leading to a higher chance of recurrence and poor outcomes. Prostate (B) and neck (D) sites are more favorable as they are easier to access for surgery and have lower rates of metastasis. Infratemporal fossa (C) is also a difficult site, but extremity tumors generally have a worse prognosis due to their anatomical and surgical challenges.

Correct Answer: B

Rationale: The correct answer is B: Ensure that valid consent is in the medical record. This is the priority because obtaining informed consent is a legal and ethical requirement before any invasive procedure like a bone marrow aspiration and biopsy. Without valid consent, the procedure cannot proceed. Administering pain medication (A) can be important, but ensuring consent comes first. Having the client shower (C) is not a priority before the procedure. Premedicating with sedatives (D) may not be necessary for every client and should be based on individual assessment.

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.