Endocrinology Practice Questions

Correct Answer: A

Rationale: The correct answer is A: Adrenaline. In injury to the adrenal cortex, adrenaline is least affected because it is primarily synthesized and secreted by the adrenal medulla, not the adrenal cortex. Cortisol, aldosterone, and androstenedione are hormones produced by the adrenal cortex. In adrenal cortex injury, the secretion of cortisol, aldosterone, and androstenedione would be significantly affected due to the damage to the adrenal cortex, leading to hormonal imbalance and related symptoms. Therefore, option A is the correct answer as it is not primarily secreted by the adrenal cortex and would be least affected in this scenario.

Correct Answer: D

Rationale: The correct answer is D because synthesis of thyroid hormones (T3 and T4) occurs by the coupling of iodinated tyrosine residues on thyroglobulin within thyroid follicles. Thyroglobulin acts as a precursor for thyroid hormone synthesis. Choices A, B, and C are incorrect because thyroid hormone synthesis does not occur in parafollicular cells, extracellularly in plasma, or require cholesterol for the coupling of iodinated tyrosine residues on thyroglobulin.

Correct Answer: B

Rationale: The correct answer is B: Chronic pancreatitis. Hypoglycemia is not typically associated with chronic pancreatitis as it is more related to pancreatic insufficiency and impaired glucose regulation. A: Glycogen storage disease can lead to hypoglycemia due to the inability to properly release stored glucose. C: Galactosaemia can cause hypoglycemia due to the impaired breakdown of galactose into glucose. D: Post-gastrectomy can lead to hypoglycemia due to rapid glucose absorption and altered hormonal responses.

Correct Answer: D

Rationale: The correct answer is D: Fine hairs. In secondary hypothyroidism, the pituitary gland fails to produce enough thyroid-stimulating hormone (TSH), resulting in low thyroid hormone levels. Fine hairs (or hair thinning) is a symptom of hyperthyroidism, not hypothyroidism. Normal cholesterol levels (Choice A) are seen in secondary hypothyroidism due to decreased metabolic rate. Menorrhagia (Choice B) can occur due to hormonal imbalances caused by untreated hypothyroidism. Low TSH levels (Choice C) are a characteristic feature of secondary hypothyroidism as the pituitary gland is not producing enough TSH to stimulate the thyroid gland.

Correct Answer: C

Rationale: Sertoli cells are responsible for producing and secreting Androgen binding globulin (ABG). They play a crucial role in supporting spermatogenesis by providing structural and nutritional support to developing sperm cells. ABG helps in the transport of testosterone and other androgens within the seminiferous tubules, aiding in the regulation of spermatogenesis. Testosterone is primarily produced by Leydig cells in the testes, not by Sertoli cells, making option A incorrect. Option B, Oestrogen, is mainly synthesized in the ovaries, while Sertoli cells do not produce GnRH (option D), which is secreted by the hypothalamus. Therefore, the correct answer is C, as Sertoli cells are primarily responsible for producing and secreting Androgen binding globulin.