Nokea
Pseudohypoparathyroidism is not associated with:
- A. Cataract
- B. Raised level of plasma PIH
- C. Mental retardation
- D. Reduced level of plasma phosphate
Correct Answer: B
Rationale: Pseudohypoparathyroidism is a rare genetic disorder that mimics the symptoms of hypoparathyroidism, despite normal or elevated levels of parathyroid hormone (PTH). The condition is characterized by hypocalcemia, hyperphosphatemia, and normal or elevated PTH levels. However, it is not associated with a raised level of plasma PIH (Parathyroid Inhibiting Hormone). In pseudohypoparathyroidism, the body's tissues are resistant to the action of PTH, leading to impaired calcium regulation. Other common features of pseudohypoparathyroidism may include cataract formation, mental retardation, and reduced levels of plasma phosphate.
You may also like to solve these questions
Prolonged ingestion of iodine can produce goiter, and is known as:
- A. Jod-Basedow effect
- B. Sick euthyroid syndrome
- C. Wolf-Chaikoff effect
- D. Thyrotoxicosis factitia
Correct Answer: C
Rationale: The prolonged ingestion of iodine causing goiter is known as the Wolf-Chaikoff effect. This phenomenon occurs when high levels of iodine cause a temporary inhibition of thyroid hormone synthesis, resulting in a decrease in thyroid hormone production. In some individuals, this can lead to the development of a goiter due to the lack of thyroid hormone feedback regulation. It is important to note that the Wolf-Chaikoff effect typically resolves on its own as the thyroid gland adapts to the increased iodine levels over time.
Growth hormone:
- A. induces gigantism in adults.
- B. is the only pituitary hormone synthesized from cholesterol.
- C. stimulates its own secretion.
- D. is released during sleep.
Correct Answer: D
Rationale: Growth hormone is primarily released during sleep, particularly during the first few hours of deep sleep. This release is pulsatile in nature, with the majority occurring at night. Growth hormone plays a critical role in growth, repair, and development of body tissues during periods of rest and sleep. Additionally, the secretion of growth hormone is also influenced by factors such as stress, exercise, and nutritional status.
Aldosterone:
- A. is synthesized in the zona fasciculata.
- B. is deficient in Conn's syndrome.
- C. is independent of ACTH.
- D. is suppressed by elevated potassium.
Correct Answer: D
Rationale: Aldosterone is a hormone produced in the zona glomerulosa of the adrenal cortex, not the zona fasciculata (Choice A is incorrect). Conn's syndrome, also known as primary hyperaldosteronism, is characterized by excess aldosterone secretion, not a deficiency (Choice B is incorrect). Aldosterone production is under the control of the renin-angiotensin-aldosterone system, which is stimulated by factors such as low blood pressure, low blood volume, and high potassium levels. Elevated potassium in the blood directly suppresses aldosterone production by the adrenal glands, serving as a negative feedback mechanism to maintain electrolyte balance (Choice D is correct). The synthesis of aldosterone also requires cholesterol as the precursor, rather than pregnenolone (Choice E is incorrect). Lastly, aldosterone production is regulated in part by ACTH (adrenocorticotropic hormone), as it can enhance the effects of
Anti-diuretic hormone secretion is:
- A. increased during stress.
- B. reduced during hemorrhage.
- C. reduced by increased blood osmolality.
- D. increased by alcohol.
Correct Answer: B
Rationale: Anti-diuretic hormone (ADH), also known as vasopressin, is a hormone released by the pituitary gland in response to changes in blood osmolality, blood volume, and blood pressure. During hemorrhage (significant blood loss), the body experiences a decrease in blood volume and blood pressure. In response to this decrease in blood volume, ADH secretion is increased to help the body retain water and maintain blood pressure levels. Therefore, it is incorrect to say that ADH secretion is reduced during hemorrhage.
Which of the following are causes of Addison's disease?
- A. Adrenoleukodystrophy
- B. Pyelonephritis
- C. Tuberculosis
- D. Autoimmune destruction of the adrenal cortex
Correct Answer: D
Rationale: Addison's disease, also known as primary adrenal insufficiency, is mainly caused by the autoimmune destruction of the adrenal cortex. This results in the inadequate production of hormones such as cortisol and aldosterone by the adrenal glands. While other conditions such as Adrenoleukodystrophy, Pyelonephritis, and Tuberculosis can also affect the adrenal glands, they are not known to be direct causes of Addison's disease.