What is the pathophysiologic process responsible for the decreased glomerular filtration rate in a patient with acute glomerulonephritis?

Correct Answer: B

Rationale: The correct answer is B: Immune complex deposition, increased capillary permeability, and cellular proliferation. Acute glomerulonephritis is characterized by inflammation of the glomeruli in the kidneys. This inflammation leads to the deposition of immune complexes, increased capillary permeability, and cellular proliferation, which collectively contribute to a decreased glomerular filtration rate. Choice A is incorrect as decreased renal-induced constriction of the renal arteries would not directly result in decreased glomerular filtration rate. Choice C is incorrect as necrosis of nephrons due to increased kidney interstitial hydrostatic pressure would affect kidney function differently. Choice D is incorrect as scar tissue formation in the proximal convoluted tubule due to toxin-induced collagen synthesis is not a typical feature of acute glomerulonephritis.

Correct Answer: C

Rationale: Irritable bowel syndrome (IBS) is a gastrointestinal disorder characterized by abdominal pain, bloating, and changes in bowel habits. While IBS can lead to symptoms like diarrhea or constipation, it typically does not cause anemia (choice A), is not generally associated with intestinal E. coli (choice B), and is not often associated with bloody diarrhea (choice D). However, IBS can indeed be associated with anxiety and/or depression (choice C) due to the gut-brain axis, a bidirectional communication system between the gut and the brain. This association is well-documented in IBS patients, highlighting the importance of considering psychological factors in managing the condition.

Correct Answer: D

Rationale: Colon cancer is more likely associated with blood in stool due to the presence of bleeding from the tumor in the colon. Gastroesophageal reflux (Choice A) typically presents with heartburn and regurgitation but not blood in stool. Crohn's disease (Choice B) can cause gastrointestinal symptoms, but bloody stools are more commonly associated with ulcerative colitis. Irritable bowel syndrome (Choice C) is characterized by abdominal pain, bloating, and changes in bowel habits, but it does not typically cause blood in stool. Therefore, the correct answer is D, Colon cancer.

Correct Answer: A

Rationale: The clinical findings of thin hair, exophthalmos (bulging eyes), hyperreflexia, and pretibial edema are classic manifestations of Graves disease, an autoimmune condition that results in hyperthyroidism. Choice B is incorrect because weight gain and constipation are more indicative of hypothyroidism, not hyperthyroidism seen in Graves disease. Choice C is incorrect as the symptoms described are more characteristic of hypothyroidism, not hyperthyroidism. Choice D is also incorrect as the symptoms listed are not consistent with Graves disease but rather suggest hypothyroidism.

Correct Answer: B

Rationale: The correct answer is B: Underexcretion of uric acid. In gouty arthritis, the crystallization within the synovial fluid of the affected joint is caused by the underexcretion of uric acid, leading to the accumulation and subsequent crystallization of urate crystals. Choice A, destruction of proteoglycans, is incorrect as it is not directly related to the crystallization process in gouty arthritis. Choice C, overexcretion of uric acid, is incorrect because gout is primarily associated with underexcretion or decreased excretion of uric acid rather than overexcretion. Choice D, increased absorption of uric acid, is also incorrect as the primary issue in gouty arthritis is the body's inability to properly eliminate uric acid.