Correct Answer: A

Rationale: Vascular spasm is the initial step in hemostasis, where blood vessels constrict to reduce blood flow to the injured area. This constriction helps limit blood loss until further steps like platelet plug formation and coagulation can take place. Platelet plug formation and coagulation occur after the vascular spasm, making them incorrect choices. Dissolution of the clot happens much later in the healing process, after the injury has sufficiently healed.

Correct Answer: D

Rationale: Seizures are most accurately diagnosed by EEG, which measures brain activity. Choice A is incorrect as ECG (electrocardiogram) measures heart activity, not brain activity. Choice B is incorrect as CBC (complete blood count) is a blood test and not used to diagnose seizures. Choice C is incorrect as an ECG (electrocardiogram) also measures heart activity, not brain activity, and is not the primary diagnostic tool for seizures.

Correct Answer: A

Rationale: The correct answer is A: Epoetin alfa (Epogen, Procrit). Epoetin alfa is a synthetic form of erythropoietin that stimulates red blood cell production and is commonly used to treat anemia in patients with chronic renal failure. By increasing red blood cell production, epoetin alfa helps raise hemoglobin levels in these patients. Pentoxifylline (Choice B) is not indicated for raising hemoglobin levels in chronic renal failure patients; it is a peripheral vasodilator used to improve blood flow. Estazolam (Choice C) is a benzodiazepine used for treating insomnia and has no role in raising hemoglobin levels. Dextromethorphan hydrobromide (Choice D) is a cough suppressant and is not used to raise hemoglobin levels in patients with chronic renal failure.

Correct Answer: B

Rationale: The correct answer is B: Altered level of consciousness. Changes in consciousness are the most sensitive indicator of altered brain function as they can signal underlying neurological issues. Option A, the ability to perform complex mathematics, though it involves brain function, is not as sensitive or direct an indicator as altered consciousness. Option C, the lack of cerebrospinal fluid production, is more related to conditions like hydrocephalus rather than a direct indicator of altered brain function. Option D, intact cranial nerve functions, indicate the normal functioning of peripheral nerves and are not as sensitive to changes in brain function as alterations in consciousness.

Correct Answer: D

Rationale: The correct answer is D. Spinal cord injuries commonly occur due to hyperextension, hyperflexion, and compression. Hyperextension and hyperflexion refer to the excessive bending or stretching of the spinal cord, while compression is the exertion of pressure on the spinal cord. These mechanisms can lead to damage such as contusions, lacerations, and compression of the spinal cord. Choices A, B, and C are incorrect as they do not accurately represent the major mechanisms of spinal cord injuries.