Which condition is characterized by high blood glucose levels?

Correct Answer: A

Rationale: The correct answer is A: diabetes mellitus. This condition is characterized by high blood glucose levels due to either insufficient insulin production or the body's inability to use insulin effectively. In diabetes, glucose cannot enter cells for energy, leading to elevated blood sugar levels. Hypoglycemia (B) is low blood sugar levels, opposite of the question. Hypothyroidism (C) is a condition involving an underactive thyroid gland, not directly related to blood glucose levels. Hyperthyroidism (D) is an overactive thyroid gland, also not directly linked to high blood glucose levels.

Correct Answer: D

Rationale: The correct answer is D: Estrogens. When extracellular fluid volume decreases, the body activates the renin-angiotensin-aldosterone system to retain water and sodium. Estrogen is not directly involved in regulating fluid balance, so its secretion would be least affected. CRH (choice A) stimulates the release of cortisol, which affects fluid balance. Arginine vasopressin (choice B) regulates water reabsorption in the kidneys. Dehydroepiandrosterone (choice C) is a precursor to sex hormones, including estrogen.

Correct Answer: B

Rationale: The correct answer is B: antidiuretic hormone (ADH). ADH is released by the posterior pituitary gland to regulate water balance in the body by controlling the reabsorption of water in the kidneys. Thyroid hormone (A) is produced by the thyroid gland, while glucagon (C) and insulin (D) are produced by the pancreas to regulate blood sugar levels. ADH is the only hormone among the choices that is released by the posterior pituitary gland, making it the correct answer.

Correct Answer: A

Rationale: The correct answer is A: glucagon; liver. Alpha cells of the pancreas secrete glucagon, which targets the liver. Glucagon helps increase blood glucose levels by promoting glycogen breakdown in the liver. Melatonin is a hormone produced by the pineal gland, not the pancreas, and does not target the liver. Glucagon does not target the kidney, and calcitonin is produced by the thyroid gland and is involved in regulating calcium levels, not blood glucose levels.

Correct Answer: D

Rationale: The correct answer is D: adrenocorticotropic hormone (ACTH). ACTH is released by the pituitary gland in response to stress or low cortisol levels, stimulating the adrenal glands to release cortisol. Aldosterone (A) regulates electrolyte balance, angiotensin (B) regulates blood pressure, and antidiuretic hormone (C) regulates water balance, but they do not directly stimulate cortisol release. So, ACTH is the correct choice for stimulating cortisol production.