Nokea
Parathyroid hormone:
- A. increases deposition of calcium in bones.
- B. causes development of goitre.
- C. is the molecule formed when T4 and T3 are degraded.
- D. is secreted in increased amounts when blood calcium level is below normal.
Correct Answer: D
Rationale: Parathyroid hormone (PTH) is a hormone produced by the parathyroid glands in response to low blood calcium levels. Its main function is to raise calcium levels in the blood by acting on the bones, kidneys, and intestines. PTH stimulates the release of calcium from the bones, enhances the absorption of calcium by the intestines, and promotes the reabsorption of calcium by the kidneys. Therefore, it is secreted in increased amounts when blood calcium levels are below normal in order to maintain overall calcium balance in the body.
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Excess prolactin causes:
- A. Acromegaly
- B. Gynecomastia
- C. Dwarfism
- D. Early Menopause
Correct Answer: B
Rationale: Excess prolactin typically causes gynecomastia in men. Prolactin is a hormone primarily responsible for milk production in women. However, in men, elevated levels of prolactin can lead to various symptoms, with gynecomastia being one of the most common. Gynecomastia is the development of breast tissue in males, which can result in swelling and tenderness of the breasts. It is important to investigate the underlying cause of elevated prolactin levels as it could be due to various conditions such as pituitary tumors, certain medications, or thyroid disorders.
Which of the following are causes of nephrogenic diabetes insipidus?
- A. Sheehan's syndrome
- B. Lithium
- C. Mutations in the vasopressin (ADH) receptor gene
- D. Mutations in vasopressin gene
Correct Answer: B
Rationale: Nephrogenic diabetes insipidus (NDI) is a condition where the kidneys are unable to respond to antidiuretic hormone (ADH) as they should, leading to excessive urination and extreme thirst. One of the main causes of nephrogenic diabetes insipidus is the use of certain medications, with lithium being the most common culprit. Lithium can interfere with the kidney's response to ADH, resulting in decreased water reabsorption and the characteristic symptoms of diabetes insipidus. Other causes of NDI can include genetic mutations affecting the vasopressin receptor gene or other underlying conditions such as hypercalcemia, hypokalemia, or obstructive uropathy.
What is Addison's disease?
- A. Addison's disease is a long-term endocrine disorder in which the adrenal glands do not produce enough steroid hormones.
- B. Addison's disease involves the overproduction of cortisol and aldosterone by the adrenal cortex.
- C. Addison's disease involves the overproduction of androgens by the adrenal medulla.
- D. Addison's disease involves the underproduction of androgens by the adrenal medulla.
Correct Answer: A
Rationale: Addison's disease, also known as primary adrenal insufficiency, is a condition where the adrenal glands do not produce enough steroid hormones, mainly cortisol and sometimes aldosterone. This deficiency in steroid hormone production is typically caused by autoimmune destruction of the adrenal cortex. Without enough cortisol and aldosterone, various symptoms may arise, such as fatigue, weight loss, low blood pressure, and skin discoloration. Therefore, option A accurately describes the nature of Addison's disease.
Upper segment > lower segment of body is found in all (in dwarfism) except:
- A. Pituitary dwarf
- B. Cretinism
- C. Achondroplasia
- D. Juvenile myxedema
Correct Answer: D
Rationale: In dwarfism conditions, the upper body segment being greater than the lower body segment is a characteristic feature seen in Achondroplasia. This condition results in a disproportionately short stature with short limbs but a trunk of normal length.
Which of the following are common symptoms of hyperthyroidism?
- A. Tremor
- B. Weight gain
- C. Heat intolerance
- D. Diarrhoea
Correct Answer: A
Rationale: Tremor (A): Tremors or shaky hands are common symptoms of hyperthyroidism. This is due to the increased metabolic rate caused by excess thyroid hormone in the body.