Nokea
Multiple sclerosis manifests as asymmetrical and in different parts of the body because:
- 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: A
Rationale: The correct answer is A. Multiple sclerosis is characterized by the immune system attacking the myelin sheath in the central nervous system. This attack leads to patchy damage on the myelin sheath, resulting in asymmetrical neurological symptoms. Choices B, C, and D are incorrect because they do not accurately describe the pathophysiology of multiple sclerosis. In multiple sclerosis, it is the autoreactive lymphocytes that target and damage the myelin sheath, not acetylcholine receptors, T lymphocytes, or cortical motor cells.
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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. In patients like the one described with a history of heart transplant and receiving long-term steroids, who are immunocompromised, live attenuated vaccines are contraindicated. Live vaccines contain weakened (attenuated) forms of the virus or bacteria, which can replicate and cause mild infections in healthy individuals but can lead to serious infections in immunocompromised individuals. Choices B, C, and D are incorrect because attenuated vaccines are not mutated, not inactive, and not pathogenic in healthy individuals, respectively.
Which of the following disorders is more likely to be associated with blood in the stool?
- A. Gastroesophageal reflux
- B. Crohn's disease
- C. Irritable bowel syndrome
- D. Colon cancer
Correct Answer: D
Rationale: The correct answer is D, Colon cancer. Colon cancer commonly presents with blood in the stool due to bleeding from the tumor. Gastroesophageal reflux (Choice A) is associated with heartburn and regurgitation of stomach contents into the esophagus. Crohn's disease (Choice B) is a type of inflammatory bowel disease that can cause symptoms like abdominal pain, diarrhea, and weight loss, but it does not typically present with blood in the stool as a primary symptom. Irritable bowel syndrome (Choice C) is a functional gastrointestinal disorder characterized by symptoms such as abdominal pain, bloating, and changes in bowel habits, but it does not usually involve blood in the stool as a prominent feature.
In which patient is alpha-1 antitrypsin deficiency the likely cause of chronic obstructive pulmonary disease?
- A. A 30-year-old who has smoked for 3 years
- B. A 65-year-old man who worked as a taxi driver most of his life
- C. A 70-year-old woman who smoked for 40 years
- D. A 50-year-old with exposure to secondhand smoke
Correct Answer: A
Rationale: The correct answer is A. Alpha-1 antitrypsin deficiency is a genetic condition that can lead to COPD at a young age, even in light smokers. Choice B is less likely as the patient's occupation does not directly correlate with alpha-1 antitrypsin deficiency. Choice C, a 70-year-old woman with a long smoking history, is more likely to have COPD due to smoking rather than alpha-1 antitrypsin deficiency. Choice D, exposure to secondhand smoke, is not a common cause of alpha-1 antitrypsin deficiency-related COPD.
Anemia of chronic inflammation is generally classified as:
- A. hypochromic and microcytic.
- B. hypochromic and macrocytic.
- C. normochromic and microcytic.
- D. normochromic and normocytic.
Correct Answer: D
Rationale: Anemia of chronic inflammation is characterized by normochromic and normocytic red blood cells. In chronic inflammation, the body typically produces enough red blood cells, but they are often smaller and paler than normal (normocytic and normochromic). Choices A, B, and C are incorrect because hypochromic and microcytic, hypochromic and macrocytic, and normochromic and microcytic anemias are not typically associated with chronic inflammation.
A patient is diagnosed with type 2 diabetes mellitus. Which of the following is a common initial treatment strategy?
- A. Insulin therapy
- B. Lifestyle modification and metformin
- C. Sulfonylureas
- D. Thiazolidinediones
Correct Answer: B
Rationale: The correct answer is B: Lifestyle modification and metformin. When managing type 2 diabetes mellitus, initial treatment often involves lifestyle changes such as adopting a healthy diet and increasing physical activity, along with the oral medication metformin. Insulin therapy (choice A) is usually reserved for cases where lifestyle changes and oral medications are not sufficient to control blood sugar levels. Sulfonylureas (choice C) and thiazolidinediones (choice D) are also oral medications used in diabetes management, but they are not typically recommended as first-line treatments due to various side effects and considerations in type 2 diabetes management.