Epinephrine (adrenaline) increases blood glucose by:

Correct Answer: C

Rationale: The correct answer is C because epinephrine stimulates the hepatic conversion of glycogen into glucose. This process, called glycogenolysis, releases stored glucose from the liver into the bloodstream, increasing blood glucose levels. Choice A is incorrect because epinephrine does not directly increase glucose transport into cells. Choice B is incorrect as gluconeogenesis is the synthesis of new glucose, not the release of stored glucose. Choice D is incorrect because fatty acids are not directly converted into glucose by epinephrine.

Correct Answer: D

Rationale: The correct answer is D: pituitary gland. The pituitary gland is often referred to as the 'master gland' because it controls the functions of other endocrine glands in the body. It secretes hormones that regulate various bodily functions such as growth, metabolism, and reproduction. It is located at the base of the brain and is divided into two parts: anterior and posterior. The anterior pituitary gland produces and releases several important hormones that influence other endocrine glands. The other choices (A: pancreas, B: adrenal glands, C: thyroid gland) do not have the same broad regulatory control over the endocrine system as the pituitary gland.

Correct Answer: A

Rationale: The correct answer is A: ADH (Antidiuretic Hormone). ADH is released in response to a nerve impulse to regulate water balance in the body by increasing water reabsorption in the kidneys. Nerve impulses trigger the release of ADH from the posterior pituitary gland. Cortisol (B) is released in response to stress, testosterone (C) is a sex hormone, and insulin (D) is released in response to high blood sugar levels, not nerve impulses.

Correct Answer: B

Rationale: The correct answer is B: To regulate serum calcium levels. The parathyroid gland secretes parathyroid hormone (PTH) to regulate calcium levels in the blood. PTH increases calcium levels by stimulating bone resorption, enhancing calcium absorption in the intestines, and promoting calcium reabsorption in the kidneys. Choices A, C, and D are incorrect because the primary function of the parathyroid gland is specifically related to calcium regulation, not general metabolic homeostasis, signaling to other glands, or receiving signals from the hypothalamus.

Correct Answer: B

Rationale: The correct answer is B: ADH (antidiuretic hormone). Diabetes insipidus is a condition characterized by excessive thirst and urination due to a deficiency of ADH, which regulates water balance in the body. Insulin (choice A) is related to diabetes mellitus, not diabetes insipidus. Growth hormone (choice C) and oxytocin (choice D) do not play a direct role in water balance regulation. Therefore, choice B is the most appropriate answer for this question.