Nokea
Which of the following is the most common cause of Cushing's disease?
- A. ACTH-producing pituitary adenoma
- B. Adrenocortical adenoma
- C. Ectopic ACTH secretion
- D. McCune-Albright syndrome
Correct Answer: A
Rationale: The most common cause of Cushing's disease is an ACTH-producing pituitary adenoma. In this condition, the pituitary gland produces excessive amounts of adrenocorticotropic hormone (ACTH), which stimulates the adrenal glands to produce high levels of cortisol. This leads to the signs and symptoms of Cushing's disease, such as weight gain, high blood pressure, and muscle weakness. Adrenocortical adenoma refers to a benign tumor of the adrenal cortex that can also cause Cushing's syndrome, but it is not as common as an ACTH-producing pituitary adenoma. Ectopic ACTH secretion occurs when a non-pituitary tumor produces ACTH, leading to Cushing's syndrome. McCune-Albright syndrome is a rare genetic disorder that can cause various endocrine abnormalities, but it is not a common cause of Cushing's disease.
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Hypocalcemia is produced by all except:
- A. Hysterical hypoventilation
- B. Acute pancreatitis
- C. Chronic renal failure
- D. Osteomalacia
Correct Answer: D
Rationale: Osteomalacia is a condition in which there is a softening of the bones due to a deficiency in vitamin D or calcium. It is not a cause of hypocalcemia, as it is a result of low levels of calcium in the bloodstream. The other options listed are potential causes of hypocalcemia:
Which one of the following statements best describes an Addisonian crisis?
- A. Severe adrenal insufficiency resulting in dangerously low serum testosterone levels
- B. Dangerously high levels of testosterone
- C. Dangerously high serum cortisol levels
- D. Severe adrenal insufficiency resulting in dangerously low serum cortisol levels
Correct Answer: D
Rationale: An Addisonian crisis, also known as an acute adrenal crisis, is a life-threatening medical emergency that occurs due to severe adrenal insufficiency, leading to a sudden drop in cortisol levels. Cortisol is a vital hormone produced by the adrenal glands, and its deficiency can result in serious symptoms such as hypotension, dehydration, electrolyte imbalances, and shock. If left untreated, an Addisonian crisis can be fatal. Therefore, the correct description of an Addisonian crisis is severe adrenal insufficiency resulting in dangerously low serum cortisol levels.
Which of the following is the underlying problem in neurogenic diabetes insipidus?
- A. Overproduction of vasopressin (antidiuretic hormone)
- B. Lack of oxytocin
- C. Overproduction of oxytocin
- D. Overproduction of prolactin
Correct Answer: E
Rationale: Neurogenic diabetes insipidus is a condition characterized by a deficiency of vasopressin (antidiuretic hormone). Vasopressin is responsible for regulating the body's water balance by controlling the reabsorption of water in the kidneys. In neurogenic diabetes insipidus, there is a problem with either the production, release, or action of vasopressin, leading to excessive urination and thirst. This condition can be caused by damage to the hypothalamus or pituitary gland, which are involved in producing and releasing vasopressin. Symptoms of neurogenic diabetes insipidus include frequent urination, excessive thirst, and dehydration.
ADH is secreted by the
- A. Hypothalamus
- B. Posterior lobe of the pituitary
- C. Intermediate Lobe of the pituitary
- D. Anterior lobe of the pituitary
Correct Answer: B
Rationale: ADH (antidiuretic hormone), also known as vasopressin, is secreted by the posterior lobe of the pituitary gland. ADH plays a key role in regulating water balance in the body by controlling the reabsorption of water in the kidneys. When the body senses a decrease in blood volume or an increase in blood osmolarity, ADH is released to signal the kidneys to conserve water, leading to concentrated urine production and water retention in the body.
Which of the following statements best describes Cushing's syndrome?
- A. Cushing's syndrome refers to a disease process caused by abnormally high levels of cortisol
- B. Cushing's syndrome refers to a disease process caused by abnormally low levels of aldosterone
- C. Cushing's syndrome refers to a disease process caused by abnormally high levels of aldosterone
- D. Cushing's syndrome refers to a disease process caused by abnormally low levels of cortisol
Correct Answer: A
Rationale: Cushing's syndrome is a condition characterized by excessive levels of cortisol in the body. Cortisol is a hormone produced by the adrenal glands that helps regulate various bodily functions, including metabolism, immune response, and stress response. When there is an overproduction of cortisol, either due to excessive production by the adrenal glands or prolonged use of corticosteroid medications, it can result in Cushing's syndrome. Symptoms of Cushing's syndrome include weight gain, particularly in the face and abdomen, high blood pressure, muscle weakness, and irregularities in menstruation. It is important to diagnose and manage Cushing's syndrome to prevent potential complications such as diabetes, osteoporosis, and cardiovascular disease.