What are the major mechanisms of spinal cord injuries?

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.

Correct Answer: C

Rationale: A tension pneumothorax is characterized by a large accumulation of trapped air in the pleural space, creating pressure that affects both the lungs and heart. This condition can lead to life-threatening consequences by shifting mediastinal structures and impairing cardiac function. Treatment involves decompressing the trapped air to relieve the tension. Choices A, B, and D are incorrect as they do not describe the primary pathophysiological mechanism of tension pneumothorax, which is the accumulation of air in the pleural space, not blood, rib fractures, or alveolar fluid accumulation.

Correct Answer: B

Rationale: A history of IV drug use is significant in cases of fever of unknown origin, as it increases the risk of infections like endocarditis, which can present with persistent fever. Smoking (Choice A) is not directly linked to FUO. While a history of STD treatment (Choice C) may be relevant, it is less likely to be associated with FUO compared to IV drug use. Family history of cardiac disease (Choice D) is not typically a primary factor in the diagnosis of FUO.

Correct Answer: A

Rationale: The correct answer is A: Bone marrow. B cells are originally derived from cells of the bone marrow. Bone marrow is the primary site where B cells develop and mature. Lymph nodes (choice B), gut-associated lymphoid tissue (choice C), and the thymus (choice D) are involved in the immune response but are not the primary site of origin for B cells.

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: B

Rationale: The correct answer is B. A cerebrovascular accident (CVA), or stroke, is often caused by a lack of blood flow to part of the brain. This leads to damage in the brain tissue due to the deprived oxygen and nutrients. Choices A, C, and D are incorrect. A blow to the head from a hard object can cause a traumatic brain injury but is not the etiology of a CVA. Excessive exercise like running does not typically lead to a stroke. A ruptured artery in the heart may result in a heart attack, not a cerebrovascular accident.

Correct Answer: A

Rationale: Polycythemia Vera, characterized by excess red blood cells, can cause tissue ischemia and necrosis due to the increased blood viscosity. This condition restricts blood flow, leading to inadequate oxygen delivery to tissues and subsequent tissue damage. Choices B, C, and D are incorrect because they are not directly associated with the pathophysiology of Polycythemia Vera.

Correct Answer: C

Rationale: Visceral pain is associated with distension, ischemia, and inflammation of internal organs. In the case of a small bowel obstruction, the intense, diffuse pain reported by the client is likely due to the distension and ischemia of the small bowel. Somatic pain (Choice A) would be more localized and sharp, typically arising from the parietal peritoneum. Referred pain (Choice B) is pain perceived at a site distant from the actual pathology. Neuropathic pain (Choice D) involves dysfunction or damage to the nervous system and is not typically associated with the described physiologic phenomenon of distension and ischemia in the context of a small bowel obstruction.

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.