Nokea
Which of the following are not causes of neurogenic diabetes insipidus?
- A. Sheehan's syndrome
- B. Mutations in the vasopressin (ADH) receptor gene
- C. Meningitis
- D. Mutations in the vasopressin gene
Correct Answer: D
Rationale: Neurogenic diabetes insipidus is due to a deficiency in vasopressin (antidiuretic hormone, ADH) production in the hypothalamus or a failure of proper vasopressin release from the posterior pituitary. Causes of neurogenic DI typically involve factors affecting vasopressin synthesis, storage, or release. However, mutations in the vasopressin gene itself would be a cause of genetic forms of diabetes insipidus, not neurogenic diabetes insipidus. Common causes of neurogenic diabetes insipidus include traumatic brain injury, brain tumors, pituitary adenomas, meningitis, and Sheehan's syndrome.
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A person with acromegaly usually has:
- A. prognathism and large fleshy lips.
- B. hypoglycemia.
- C. a growth hormone deficiency.
- D. protruding eye balls.
Correct Answer: A
Rationale: Acromegaly is a hormonal disorder that results from the overproduction of growth hormone (GH) in adulthood. One of the key physical characteristics associated with acromegaly is the enlargement of facial features. People with acromegaly often develop prognathism, which is a condition where the lower jaw protrudes forward, leading to a prominent lower face. Additionally, they may have large fleshy lips due to the soft tissue swelling that occurs as a result of excess GH. Other common signs of acromegaly include enlarged hands and feet, thickened skin, and joint pain.
Which of the following does the adrenal cortex produce?
- A. Adrenaline
- B. Aldosterone
- C. Cortisol
- D. Noradrenaline
Correct Answer: B
Rationale: The adrenal cortex is the outer region of the adrenal glands and is responsible for producing several hormones, including aldosterone. Aldosterone is a mineralocorticoid hormone that plays a crucial role in regulating electrolyte balance, particularly sodium and potassium, in the body. It helps maintain blood pressure and fluid balance by acting on the kidneys to reabsorb sodium and water while excreting potassium in the urine. Adrenaline and noradrenaline (also known as epinephrine and norepinephrine) are produced by the adrenal medulla, which is the inner region of the adrenal glands. Cortisol is another hormone produced by the adrenal cortex, but aldosterone specifically regulates electrolyte balance.
Commonest cause of 'ambiguous genitalia' in newborn is:
- A. Congenital adrenal hyperplasia
- B. True hermaphroditism
- C. Testicular ferminisation syndrome
- D. Pseudo-hermaphroditism
Correct Answer: A
Rationale: Congenital adrenal hyperplasia (CAH) is the most common cause of ambiguous genitalia in newborns. This condition is due to a deficiency of enzymes in the adrenal gland that are necessary for the production of cortisol. As a result, the body produces excess androgens (masculinizing hormones), leading to abnormal genital development in females. The external genitalia may appear ambiguous, with features of both male and female genitalia. This condition can be detected through newborn screening and confirmed through further hormonal and genetic testing. Treatment involves hormone replacement therapy to normalize hormone levels and surgery may be required to reconstruct the genitalia.
Increased gonadal production of oestrogen is seen in:
- A. Third trimester of pregnancy
- B. Congenital adrenal hyperplasia
- C. Polycystic ovarian disease
- D. Testicular feminization syndrome
Correct Answer: C
Rationale: Polycystic ovarian disease, also known as polycystic ovary syndrome (PCOS), is a common endocrine disorder characterized by increased levels of androgens (male hormones) and disrupted estrogen production in the ovaries. The hormonal imbalance seen in PCOS leads to increased gonadal production of estrogen. This condition is often associated with symptoms such as irregular menstrual cycles, infertility, acne, and excess facial or body hair growth. In contrast, the other options do not typically involve increased gonadal production of estrogen as seen in PCOS.
The posterior pituitary stores and secretes _________.
- A. anti-diuretic hormone (ADH) and oxytocin.
- B. growth hormone and thyroid-stimulating hormone.
- C. estrogen and testosterone.
- D. aldosterone and cortisol.
Correct Answer: A
Rationale: The posterior pituitary gland secretes anti-diuretic hormone (ADH) and oxytocin, which are produced in the hypothalamus and then transported and stored in the posterior pituitary before being released into the bloodstream. ADH, also known as vasopressin, helps regulate water balance in the body by controlling the reabsorption of water in the kidneys. Oxytocin, on the other hand, plays a role in various reproductive functions such as labor and lactation, as well as social bonding and behavior.