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: A

Rationale: In a patient with a subconjunctival hemorrhage secondary to allergic rhinitis, the hemorrhage is typically self-limiting and will resolve on its own within 2 weeks without the need for specific treatment. Referring the patient for immediate ophthalmologic examination is not necessary unless there are other concerning symptoms. Starting oral antihistamines may help manage the underlying allergic rhinitis but is not specifically indicated for the hemorrhage. Topical corticosteroids are not routinely prescribed for subconjunctival hemorrhage as they may have limited benefit and could potentially cause complications.

Correct Answer: A

Rationale: Crohn's disease is a type of inflammatory bowel disease that can affect any part of the digestive tract. Right lower quadrant cramping is consistent with Crohn's disease as it commonly involves the terminal ileum, which is located in the right lower quadrant of the abdomen. Severe bloody diarrhea is more characteristic of ulcerative colitis, another type of inflammatory bowel disease. Nausea and vomiting are not specific symptoms of Crohn's disease. Crohn's disease can affect any part of the digestive tract, not just the rectum, so it is not accurate to say it mostly affects the rectum.

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: B

Rationale: Acute closed-angle glaucoma presents with symptoms such as a red eye, severe pain, and rapid visual acuity changes due to increased intraocular pressure. This condition is considered an ophthalmologic emergency. Bacterial conjunctivitis typically presents with redness, discharge, and irritation but is not associated with severe pain or visual changes. Chronic open-angle glaucoma is usually asymptomatic until advanced stages and does not typically present with acute pain. Blepharitis involves inflammation of the eyelid margins and is characterized by redness and irritation, but it does not cause severe pain or acute visual changes.

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: C

Rationale: Osteosarcoma is an aggressive bone tumor that most commonly arises in the bone marrow of long bones, such as the femur or tibia. Choice A is incorrect as osteosarcoma is not a slow-growing tumor but rather a fast-growing one. Choice B is incorrect as osteosarcoma is not typically solitary but can involve multiple lesions. Choice D is incorrect as osteosarcoma primarily affects the medullary (marrow) cavity of bones, rather than infiltrating the trabeculae in spongy bone and surrounding tissue.

Correct Answer: C

Rationale: In nephritic syndrome, the presence of red blood cell casts in the urine is a characteristic finding, reflecting glomerular inflammation and damage. This differentiates it from nephrotic syndrome, where red blood cell casts are typically absent. Choice A is incorrect because nephritic syndrome usually presents with less albuminuria compared to nephrotic syndrome. Choice B is incorrect as hematuria is a common feature of nephritic syndrome. Choice D is incorrect as hypoalbuminemia is more commonly associated with nephrotic syndrome.

Correct Answer: C

Rationale: The correct answer is C: Decline in kidney function. As people age, their kidneys may not work as effectively in conserving water and concentrating urine, leading to a higher risk of dehydration. Choice A is incorrect because more insensible losses do not directly relate to an increased risk of dehydration in the elderly. Choice B, an increase in muscle mass, is not a factor that leads to dehydration. Choice D, a decrease in fat, is also not a direct factor contributing to dehydration in the elderly.