Nokea
Macular degeneration occurs as a result of:
- A. loss of lens accommodation
- B. detachment of the retina
- C. increased intraocular pressure
- D. impaired blood supply leading to cellular waste accumulation and ischemia
Correct Answer: D
Rationale: Macular degeneration is a condition that affects the macula, a part of the retina responsible for central vision. It is primarily caused by impaired blood supply to the macula, leading to cellular waste accumulation and ischemia. This results in the death of photoreceptor cells and ultimately vision loss. Choices A, B, and C are incorrect because macular degeneration is not related to the loss of lens accommodation, detachment of the retina, or increased intraocular pressure. The correct answer directly addresses the underlying pathophysiology of macular degeneration.
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Women who have breast cancer due to a BRCA1 gene mutation are usually:
- A. positive for human epidermal growth factor receptor 1 and 2.
- B. negative for estrogen receptor.
- C. positive for estrogen receptor, progesterone receptor, and human epidermal growth factor receptor 2.
- D. negative for estrogen receptor, progesterone receptor, and human epidermal growth factor receptor 2.
Correct Answer: D
Rationale: Women with breast cancer due to a BRCA1 gene mutation commonly have a triple-negative breast cancer subtype, which means they are negative for estrogen receptor, progesterone receptor, and human epidermal growth factor receptor 2 (HER2). This subtype tends to be more aggressive and harder to treat. Choice A is incorrect as they are typically negative for HER2. Choice B is incorrect because they are usually negative for estrogen receptor. Choice C is incorrect as they are usually negative for progesterone receptor and HER2.
Which of the following eye disorders manifests with red eye, pain, and visual acuity changes?
- A. Bacterial conjunctivitis
- B. Acute closed-angle glaucoma
- C. Chronic open-angle glaucoma
- D. Blepharitis
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.
In nephritic syndrome compared to nephrotic syndrome, there is:
- A. higher amounts of albuminuria.
- B. negligible hematuria or absence of hematuria.
- C. presence of red blood cell casts in the urine.
- D. hypoalbuminemia
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.
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.
Which of the following types of vitamin or mineral deficiency can cause megaloblastic anemia and is associated with lower extremity paresthesias?
- A. Vitamin B12
- B. Folate
- C. Iron
- D. Vitamin K
Correct Answer: A
Rationale: The correct answer is Vitamin B12. Vitamin B12 deficiency can lead to megaloblastic anemia, a condition characterized by the production of abnormally large and immature red blood cells. Lower extremity paresthesias, such as tingling or numbness, are common neurological symptoms associated with vitamin B12 deficiency. Folate deficiency can also cause megaloblastic anemia but is not typically linked to lower extremity paresthesias. Iron deficiency leads to microcytic anemia, not megaloblastic anemia. Vitamin K deficiency is associated with bleeding tendencies, not megaloblastic anemia or paresthesias.