Which gland is located just superior to the kidneys?

Correct Answer: B

Rationale: The correct answer is B: Adrenal gland. The adrenal gland is located just superior to the kidneys. It is part of the endocrine system and plays a crucial role in producing hormones such as cortisol and adrenaline. The pituitary gland (A) is located in the brain, the pancreas (C) is situated in the abdomen, and the ovaries (D) are found in the pelvic region. The adrenal gland's location and function make it the most appropriate choice in this scenario.

Correct Answer: D

Rationale: The correct answer is D: islets of Langerhans. These clusters of cells within the pancreas are responsible for producing insulin. Insulin is a hormone that regulates blood sugar levels. The ovaries (A) and testes (B) are not responsible for insulin production. The hypothalamus (C) plays a role in regulating many bodily functions, but it is not directly involved in insulin production.

Correct Answer: C

Rationale: Homeostasis is the maintenance of a stable internal environment to support optimal physiological functioning. It involves mechanisms that regulate variables within a narrow range. Negative feedback is a key mechanism in maintaining homeostasis by counteracting deviations from set points. Positive feedback amplifies changes and is not involved in maintaining stability. Metabolism refers to the chemical processes in the body and is not specifically related to the maintenance of internal stability. Therefore, the correct answer is C (homeostasis) because it directly relates to the concept of maintaining a stable internal environment through regulatory mechanisms.

Correct Answer: A

Rationale: Step 1: Identify the symptoms described in the patient: Moon face, truncal obesity, hypertension, purple striae, buffalo hump, fragile skin, impaired glucose tolerance. Step 2: These symptoms are classic for Cushing's syndrome, which is caused by excess cortisol. Step 3: The opposite of increased cortisol levels is decreased cortisol levels. Step 4: Addison's disease is characterized by adrenal insufficiency, leading to decreased cortisol levels. Step 5: Therefore, the correct answer is A: Addison's disease. Summary: - B: Pheochromocytoma is a tumor of the adrenal medulla, causing excess catecholamines, not related to cortisol. - C: Hyperaldosteronism is excess aldosterone production, not related to cortisol. - D: Cushing's syndrome is characterized by excess cortisol, not the opposite.

Correct Answer: B

Rationale: The correct answer is B because peptide hormones are hydrophilic and cannot pass through the cell membrane. Therefore, their receptors must be located on the cell's outer membrane to bind and trigger intracellular signaling pathways. Option A is incorrect because hydrophobic hormones can directly pass through the cell membrane, so their receptors are typically inside the cell. Option C is incorrect because hydrophobic hormones do not require a receptor on the cell's outer membrane. Option D is incorrect because hydrophilic hormones, like peptide hormones, require receptors on the cell's outer membrane.