How does rivaroxaban (Xarelto) work?

Correct Answer: A

Rationale: The correct answer is A because rivaroxaban is a direct factor Xa inhibitor that works by inhibiting thrombin formation. Thrombin is a key enzyme in the blood coagulation pathway, and by inhibiting it, rivaroxaban prevents the formation of fibrin clots. Choices B and D are incorrect because rivaroxaban does not directly inhibit fibrinogen or work against vitamin K. Choice C is also incorrect as rivaroxaban does not actually "thin" the blood but rather prevents the formation of clots by inhibiting thrombin.

Correct Answer: D

Rationale: The correct answer is D: An HIV infection. The presence of antibodies to the AIDS virus in the blood indicates that the client has been exposed to HIV and their immune system has produced antibodies against it. This does not mean the client is immune to HIV (choice A) as HIV infection can still occur. It also does not necessarily mean the immune system is intact (choice B) as the presence of antibodies can indicate exposure to the virus. Additionally, the presence of antibodies does not indicate the client has an AIDS-related complication (choice C) as AIDS is a later stage of HIV infection.

Correct Answer: B

Rationale: The correct answer is B because during the primary infection stage of HIV, the virus replicates rapidly without significant antibody production. This results in a high viral load but a lack of detectable HIV-specific antibodies. This stage is also known as the window period. Choice A is incorrect because the client's antibodies are not yet successful in killing the virus during the primary infection stage. Choice C is incorrect because the risk for opportunistic infections typically increases during the later stages of HIV when the immune system is severely compromised, not during the primary infection stage. Choice D is incorrect because once a person is infected with HIV, they will always have the virus, it does not spontaneously clear on its own.

Correct Answer: B

Rationale: The correct answer is B: Children with iron deficiency anemia are more susceptible to infection than are other children. Iron is crucial for the immune system to function optimally. In iron deficiency anemia, the body lacks enough iron to produce hemoglobin, which can impair the immune response, making individuals more prone to infections. Therefore, children with iron deficiency anemia are indeed more susceptible to infections. Explanation of other choices: A: Little is known about iron-deficiency anemia and its relationship to infection in children - This is incorrect as there is a clear understanding of the link between iron deficiency anemia and susceptibility to infections. C: Children with iron-deficiency anemia are less susceptible to infection than are other children - This is incorrect as iron deficiency impairs the immune response, making individuals more susceptible to infections. D: Children with iron-deficient anemia are equally as susceptible to infection as are other children - This is incorrect as iron deficiency compromises the immune system, leading to increased susceptibility to

Correct Answer: C

Rationale: The correct answer is C: Overproduction of red blood cells. Polycythemia vera is characterized by the excessive production of red blood cells in the bone marrow, leading to an increased number of red blood cells in the bloodstream. This condition can result in thickening of the blood, increased risk of blood clots, and potential complications such as stroke or heart attack. Explanation of why other choices are incorrect: A: Underproduction of white blood cells - Polycythemia vera does not involve a decrease in white blood cell production. B: Underproduction of platelets - Polycythemia vera does not lead to a decrease in platelet production. D: Overproduction of bone cells - Polycythemia vera does not affect the production of bone cells; it specifically involves the overproduction of red blood cells.