Identify an endocrine gland within the brain.

Correct Answer: C

Rationale: The correct answer is C: Pituitary gland. The pituitary gland is an endocrine gland located at the base of the brain, below the hypothalamus. It secretes various hormones that regulate important functions in the body. The other choices are incorrect because: A: Adrenal gland - located on top of the kidneys, not in the brain. B: Pancreas - located in the abdomen, not in the brain. D: Parathyroid glands - located in the neck, not in the brain.

Correct Answer: D

Rationale: The correct answer is D: adrenal gland. The adrenal gland secretes cortisol and aldosterone. Cortisol is essential for regulating metabolism, immune response, and stress. Aldosterone helps regulate blood pressure and electrolyte balance. The other choices are incorrect because the thyroid gland (A) secretes hormones like thyroid hormone and calcitonin, the parathyroid gland (B) secretes parathyroid hormone, and the pancreas (C) secretes insulin and glucagon. Only the adrenal gland (D) secretes cortisol and aldosterone, making it the correct answer.

Correct Answer: B

Rationale: The correct answer is B: pancreas; glucagon. When blood glucose levels are low, the pancreas secretes glucagon. Glucagon acts to increase blood glucose levels by stimulating the liver to release stored glucose. The adrenal cortex does not directly regulate blood glucose levels through aldosterone secretion. Insulin is secreted by the pancreas in response to high blood glucose levels to lower them, not increase them. The posterior pituitary secretes ADH to regulate water balance, not blood glucose levels.

Correct Answer: B

Rationale: Rationale: Glucagon stimulates the breakdown of glycogen stored in the liver into glucose, increasing blood glucose levels. This process, called glycogenolysis, is crucial during times of low blood sugar to maintain energy levels. Therefore, choice B is correct. Choices A, C, and D are incorrect because glucagon does not directly affect protein synthesis within cells, decrease glycogen conversion into glucose, or slow down glucose formation from lactic acid.

Correct Answer: A

Rationale: Rationale for Correct Answer A: Diabetes Mellitus is a condition where the body cannot properly regulate blood sugar levels due to insufficient insulin production. This leads to increased breakdown of fats for energy, resulting in the production of ketone bodies. Ketone bodies are acidic and are excreted in urine, causing ketonuria. Therefore, the correct answer is A. Summary of Incorrect Choices: B: Ketone bodies do not decrease in urine in Diabetes Mellitus. C: Urine does not become more dilute in Diabetes Mellitus; instead, it may become more concentrated due to increased excretion of glucose and ketone bodies. D: This choice is incorrect as Diabetes Mellitus does affect urine composition by increasing ketone bodies.