Which of the following is NOT true of growth hormone?

Correct Answer: C

Rationale: The correct answer is C: growth hormone does not promote glucose metabolism. Growth hormone primarily promotes protein synthesis in bones, cartilage, and muscles (B), stimulates the rate of amino acid entrance into the cell (A), and promotes fat metabolism (D). Glucose metabolism is mainly regulated by insulin, not growth hormone.

Correct Answer: D

Rationale: Sure! The correct answer is D because type I diabetes (IDDM) is characterized by the body's inability to produce insulin, leading to high blood sugar levels. Insulin injections are necessary to replace the missing insulin. A is incorrect because type I diabetes is not associated with obesity. B is incorrect because type II diabetes is actually the most common form. C is incorrect because in type I diabetes, the body's cells do not produce insulin, rather than not responding to it.

Correct Answer: C

Rationale: The correct answer is C: Epinephrine and norepinephrine. These hormones are responsible for the 'fight-or-flight' response. When the body perceives a threat, these hormones are released by the adrenal glands, preparing the body for a rapid response to danger. Epinephrine increases heart rate, blood pressure, and blood flow to muscles, while norepinephrine helps maintain alertness and focus. Choice A (Thyroxine and melatonin) are hormones involved in regulating metabolism and sleep-wake cycles, not the 'fight-or-flight' response. Choice B (Insulin and glucagon) are hormones that regulate blood sugar levels, not the 'fight-or-flight' response. Choice D (Oestrogen and progesterone) are reproductive hormones that regulate the menstrual cycle and pregnancy, not the 'fight-or-flight' response.

Correct Answer: A

Rationale: The correct answer is A because somatostatin inhibits the release of both insulin and glucagon. This hormone acts as a regulator of the endocrine system by suppressing the secretion of these hormones. By inhibiting the release of insulin, somatostatin helps to prevent hypoglycemia, while inhibiting glucagon release helps to maintain blood glucose levels. Choices B, C, and D are incorrect because they do not accurately reflect the function of somatostatin in regulating the release of insulin and glucagon. B stimulates the release of both hormones, C stimulates glucagon while inhibits insulin, and D inhibits glucagon while stimulates insulin, which are all contradictory to the known actions of somatostatin.

Correct Answer: D

Rationale: The liberation of proteins to free amino acids occurs primarily in the small intestine lumen. In the stomach, proteins are broken down into smaller peptides but not fully liberated to amino acids. The enterocyte cytoplasm is where amino acids are absorbed. The brush border aids in absorption but doesn't release proteins to amino acids. Therefore, the correct answer is D (stomach) as it is not the site for the final step of protein digestion.