Nokea
The early stages of atheroma development are characterized by:
- A. macrophages full of oxidized low-density lipoprotein (LDL; i.e., foam cells) in the intima
- B. accumulation of lipids in the intima (i.e., fatty streak)
- C. accumulation of proteins such as collagen and elastin (i.e., fibrous cap)
- D. development of calcium and a necrotic lipid core
Correct Answer: A
Rationale: The correct answer is A. In the early stages of atheroma development, macrophages accumulate oxidized low-density lipoprotein (LDL) and transform into foam cells, leading to the formation of fatty streaks in the intima of blood vessels. This process is a hallmark of the initial stages of atherosclerosis. Choice B is incorrect as it describes the accumulation of lipids in the intima, which is a later event following foam cell formation. Choice C is also incorrect as it refers to the accumulation of proteins forming the fibrous cap, which occurs at a later stage to stabilize the atheroma. Choice D is incorrect as it describes the development of calcium and a necrotic lipid core, typically seen in advanced atherosclerosis rather than the early stages.
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A 30-year-old man has a history of heart transplant and is receiving long-term steroids to prevent rejection. The patient is due for routine vaccines. Attenuated vaccines are contraindicated in this patient because the antigen is:
- A. live and can cause infection.
- B. mutated and infectious.
- C. inactive but still infectious
- D. pathogenic
Correct Answer: A
Rationale: The correct answer is A: live and can cause infection. Patients who are immunocompromised, like those receiving long-term steroids after an organ transplant, should not receive live vaccines because the live attenuated organisms in these vaccines can cause infections in individuals with weakened immune systems. Choice B is incorrect because attenuated vaccines are live but weakened, not mutated. Choice C is incorrect because while inactive, attenuated vaccines are not infectious. Choice D is incorrect because attenuated vaccines are not pathogenic; they are attenuated (weakened) forms of the pathogen.
Why does multiple sclerosis manifest as asymmetrical and in different parts of the body?
- A. Autoreactive lymphocytes are causing diffuse patchy damage to the myelin sheath in the central nervous system.
- B. Acetylcholine receptors are destroyed by immunoglobulin G.
- C. Autoreactive T lymphocytes cause progressive loss of neurons in the substantia nigra.
- D. Cortical motor cells degenerate.
Correct Answer: C
Rationale: Multiple sclerosis is characterized by the immune system mistakenly attacking the myelin sheath in the central nervous system. This results in the formation of lesions that can occur in different parts of the central nervous system, leading to varied symptoms depending on the location of the damage. Choice A is the correct answer because it accurately describes the pathophysiology of multiple sclerosis. Choices B, C, and D are incorrect because they describe mechanisms or locations that are not associated with the pathogenesis of multiple sclerosis.
Canola oil produced from genetically modified canola plants altered to be herbicide-resistant is an example of a:
- A. pesticide-free food.
- B. saturated fat food.
- C. genetically modified food.
- D. product that is pure.
Correct Answer: C
Rationale: The correct answer is 'genetically modified food.' Canola oil derived from genetically modified canola plants falls into this category because the plant's genome has been altered to exhibit herbicide resistance. This genetic modification makes it a genetically modified food. Choice A, 'pesticide-free food,' is incorrect as the genetic modification is to resist herbicides, not pesticides. Choice B, 'saturated fat food,' is incorrect as it does not accurately describe the genetic modification of the canola plants. Choice D, 'product that is pure,' is too vague and does not address the genetic modification aspect of the canola plants.
What is the pathophysiologic process responsible for the decreased glomerular filtration rate in a patient with acute glomerulonephritis?
- A. Decreased renal-induced constriction of the renal arteries
- B. Immune complex deposition, increased capillary permeability, and cellular proliferation
- C. Necrosis of 70% or more of the nephrons secondary to increased kidney interstitial hydrostatic pressure
- D. Scar tissue formation throughout the proximal convoluted tubule secondary to toxin-induced collagen synthesis
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.
In which patients would the manifestation of a headache be a sign of a serious underlying disorder?
- A. A 55-year-old man with new onset of headaches that are worse at night and reported mood swings according to his family
- B. A 30-year-old woman with a unilateral throbbing headache with photophobia and nausea
- C. A 60-year-old man with his head feeling full and throbbing and muscle aching around his neck and shoulders
- D. A 40-year-old woman who experiences food cravings, gets irritable, and then develops a pulsatile-like headache on the right side of her head
Correct Answer: A
Rationale: In this scenario, the correct answer is the 55-year-old man with new onset headaches that worsen at night and reported mood swings according to his family. These symptoms, especially when combined with nighttime worsening and mood changes, could indicate a serious underlying disorder such as a brain tumor or increased intracranial pressure. Choice B is incorrect as the unilateral throbbing headache with photophobia and nausea is suggestive of migraine headaches, which are usually not associated with serious underlying disorders. Choice C describes symptoms that are more indicative of tension-type headaches rather than a serious underlying disorder. Choice D presents symptoms that are more likely related to hormonal changes and migraines rather than a serious underlying disorder.