Hyposecretion of adrenal cortex hormones can lead to ___.

Correct Answer: A

Rationale: The correct answer is A: Addison disease. Hyposecretion of adrenal cortex hormones can lead to Addison disease, characterized by fatigue, weight loss, low blood pressure, and skin discoloration. This is because insufficient cortisol and aldosterone production from the adrenal cortex can disrupt the body's stress response and electrolyte balance. Summary of why other choices are incorrect: B: Diabetes mellitus is primarily related to insulin regulation issues, not adrenal cortex hormones. C: Cushing syndrome is caused by hypersecretion, not hyposecretion, of adrenal cortex hormones. D: Cretinism is associated with thyroid hormone deficiency, not adrenal cortex hormone deficiency.

Correct Answer: D

Rationale: The correct answer is D: Cretinism. Hypothyroidism in children can lead to cretinism, a condition characterized by stunted growth, intellectual disability, and other developmental delays. This occurs because thyroid hormones play a crucial role in growth and brain development during childhood. Goiter (A) is an enlargement of the thyroid gland, not a direct consequence of hypothyroidism in children. Acromegaly (B) is caused by excess growth hormone, not by hypothyroidism. Myxedema (C) is a condition seen in adults with untreated hypothyroidism, not specifically in children.

Correct Answer: A

Rationale: The correct answer is A: Aldosterone. The adrenal cortex is responsible for producing aldosterone, a hormone that regulates blood pressure and electrolyte balance. Aldosterone is specifically produced in the zona glomerulosa layer of the adrenal cortex. Adrenaline (Choice B) is produced by the adrenal medulla, not the cortex. Glucagon (Choice C) is produced by the pancreas, not the adrenal cortex. Calcitonin (Choice D) is produced by the thyroid gland, not the adrenal cortex. Therefore, the correct answer is A because aldosterone is the hormone produced by the adrenal cortex.

Correct Answer: C

Rationale: The correct answer is C: GIP (glucose-dependent insulinotropic peptide). GIP is an incretin hormone released from the small intestine in response to glucose ingestion, stimulating insulin secretion from pancreatic beta cells. Gastrin (A), CCK (B), and secretin (D) are gastrointestinal hormones that do not directly influence insulin secretion. GIP plays a crucial role in regulating blood sugar levels by promoting insulin release, making it the most important hormone in insulin secretion.

Correct Answer: A

Rationale: The correct answer is A because blood vessels in the gut are primarily innervated by sympathetic and parasympathetic fibers, not by enteric nerves. Enteric nerves are confined to the gastrointestinal tract itself and are responsible for regulating gut motility, secretion, and blood flow. Sympathetic innervation typically causes vasoconstriction, while parasympathetic innervation promotes vasodilation. The myenteric plexus (Auerbach's plexus) lies between the longitudinal and circular muscle layers, regulating gut motility. Parasympathetic supply to the gut is mainly through the vagus nerve (cranial nerve X) and sacral nerves (pelvic splanchnic nerves). Sympathetic supply can either be inhibitory or excitatory, but generally, sympathetic fibers are inhibitory on cholinergic postganglionic fibers in the gut.