What causes osteoporosis?
- A. Poor nutrition in infancy
- B. Regularly weight-bearing exercise
- C. Bone loss, frequently during aging
- D. Cerebral palsy and associated disorders
Correct Answer: C
Rationale: The correct answer is C. Osteoporosis is commonly caused by bone loss that occurs with aging, leading to brittle bones. Choice A, poor nutrition in infancy, is not a direct cause of osteoporosis. Choice B, regularly weight-bearing exercise, actually helps in maintaining bone density and strength, reducing the risk of osteoporosis. Choice D, cerebral palsy and associated disorders, is not a common cause of osteoporosis.
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What typically causes contact dermatitis?
- A. Fungal infection
- B. Long-term disorder from gout
- C. Contact with a skin allergen
- D. Staphylococcal infection
Correct Answer: C
Rationale: Contact dermatitis is typically caused by contact with a skin allergen that triggers an allergic reaction. Choice A, fungal infection, is incorrect as contact dermatitis is not caused by fungi. Choice B, long-term disorder from gout, is also incorrect as gout is not typically associated with contact dermatitis. Choice D, Staphylococcal infection, is incorrect as contact dermatitis is primarily an allergic reaction rather than a bacterial infection.
An imbalance of which of the following hormones could lead to increased calcium levels in the blood?
- A. Parathyroid hormone
- B. Antidiuretic hormone
- C. Calcitonin
- D. Melatonin
Correct Answer: A
Rationale: The correct answer is Parathyroid hormone (Choice A). Parathyroid hormone plays a key role in regulating calcium levels in the blood. When there is an imbalance in parathyroid hormone secretion, it can lead to increased calcium levels in the blood. Antidiuretic hormone (Choice B) is involved in regulating water balance, not calcium levels. Calcitonin (Choice C) helps lower blood calcium levels and is unlikely to cause an increase. Melatonin (Choice D) regulates sleep-wake cycles and does not have a direct effect on calcium levels in the blood.
Hematopoiesis occurs primarily in the bone marrow. What cells are formed during this process?
- A. Pancreatic beta cells
- B. Red blood cells
- C. Gastric parietal cells
- D. Neurons and glial cells
Correct Answer: B
Rationale: The correct answer is B: Red blood cells. Hematopoiesis is the process of blood cell formation that primarily occurs in the bone marrow. Red blood cells are one of the main cell types formed during this process. Pancreatic beta cells (Choice A), gastric parietal cells (Choice C), and neurons and glial cells (Choice D) are not formed during hematopoiesis. Pancreatic beta cells are involved in insulin production, gastric parietal cells secrete gastric acid, and neurons and glial cells are part of the nervous system.
When arterial blood pressure declines, the kidneys secrete a hormone to increase blood pressure and peripheral resistance. What is this hormone called?
- A. Renin
- B. Antidiuretic hormone
- C. Atrial natriuretic
- D. Insulin
Correct Answer: A
Rationale: Renin is the correct answer. When arterial blood pressure decreases, the kidneys release renin, which triggers a series of reactions ultimately leading to an increase in blood pressure and peripheral resistance. Antidiuretic hormone (choice B) is involved in water retention, atrial natriuretic hormone (choice C) promotes sodium excretion and lowers blood pressure, and insulin (choice D) regulates glucose metabolism, not blood pressure.
How does influenza immunization produce immunity?
- A. The virus from the vaccine remains in the body until the end of the season
- B. An attenuated virus causes immune system suppression and triggers immunity
- C. The body identifies the virus and develops antibodies against the virus
- D. The vaccine remains in the injection site and produces immune cells
Correct Answer: C
Rationale: The correct answer is C. Influenza immunization works by introducing a weakened or inactivated form of the virus into the body, allowing the immune system to recognize it as foreign. This recognition triggers the production of antibodies specific to the virus. Choice A is incorrect as the virus in the vaccine does not remain in the body until the end of the season. Choice B is incorrect as an attenuated virus does not cause immune system suppression but rather stimulates an immune response. Choice D is incorrect because the vaccine does not stay at the injection site but rather prompts a systemic immune response throughout the body.