Nokea
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.
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Which cranial nerve is not involved in acromegaly?
- A. VIII
- B. III, IV, VI
- C. V
- D. Il
Correct Answer: A
Rationale: Acromegaly is a disorder caused by the overproduction of growth hormone in adulthood, usually due to a pituitary tumor. The cranial nerves that may be affected in acromegaly are Cranial Nerves III, IV, VI (oculomotor, trochlear, abducens) due to compression of the optic chiasm by the expanding tumor. Cranial Nerve V (trigeminal nerve) may also be affected given its close proximity to the pituitary gland. However, Cranial Nerve VIII (vestibulocochlear nerve) is not typically involved in acromegaly.
Cushing's syndrome does not give rise to:
- A. Hirsutism
- B. Peripheral neuropathy
- C. Purple striae
- D. Acne
Correct Answer: B
Rationale: Cushing's syndrome is a disorder caused by prolonged exposure to high levels of cortisol hormone. While Cushing's syndrome can manifest with a variety of symptoms, peripheral neuropathy is not a typical feature of this condition. Cushing's syndrome is commonly associated with symptoms such as hirsutism (excessive hair growth), purple striae (skin stretch marks that are purple in color), and acne due to the hormonal imbalances it creates. Peripheral neuropathy, which involves damage to the peripheral nerves leading to symptoms like numbness, tingling, and weakness in the extremities, is not a characteristic symptom of Cushing's syndrome.
Which of the following is the most potent stimulus for hypothalamic production of arginine vasopressin?
- A. Hypertonicity
- B. Hyperkalemia
- C. Hypokalemia
- D. Hypotonicity
Correct Answer: A
Rationale: Hypertonicity (increased osmolarity or high concentration of solutes in the blood) is the most potent stimulus for the hypothalamic production of arginine vasopressin (also known as antidiuretic hormone or ADH). When the body senses increased plasma osmolality, the osmoreceptors in the hypothalamus stimulate the release of vasopressin from the posterior pituitary gland. Vasopressin acts on the kidneys to increase water reabsorption and decrease urine output, helping to restore normal osmolarity. This mechanism helps to conserve water and maintain body fluid balance in response to dehydration or increased solute concentration in the blood.
All of the following are associated with hyperuricemia except:
- A. Cardiovascular disease
- B. Gouty arthritis
- C. Nephrolithiasis
- D. Peripheral neuropathy
Correct Answer: D
Rationale: Hyperuricemia is a medical condition characterized by elevated levels of uric acid in the blood. This can lead to the formation of urate crystals, which are responsible for various health problems. The three main conditions associated with hyperuricemia are cardiovascular disease (A), gouty arthritis (B), and nephrolithiasis (C).
Cortisol secretion is directly stimulated by:
- A. Aldosterone
- B. Prolactin
- C. ACTH
- D. CRH
Correct Answer: C
Rationale: Cortisol secretion is directly stimulated by adrenocorticotropic hormone (ACTH), which is produced and released by the anterior pituitary gland in response to corticotropin-releasing hormone (CRH) from the hypothalamus. ACTH acts on the adrenal cortex to stimulate the production and release of cortisol. Aldosterone is another hormone produced by the adrenal cortex, but it is not directly involved in the stimulation of cortisol secretion. Prolactin is a hormone produced by the pituitary gland that plays a role in lactation, not cortisol secretion. High blood potassium levels can stimulate aldosterone secretion but do not directly stimulate cortisol secretion.