Which part of pancreas lies near the hilum of the spleen?

Correct Answer: D

Rationale: Step 1: The pancreas is an elongated organ located behind the stomach. Step 2: The tail of the pancreas is the left end of the organ and is closest to the hilum of the spleen. Step 3: The spleen and the tail of the pancreas are adjacent to each other in the upper left quadrant of the abdomen. Step 4: Therefore, the correct answer is D: Tail. Summary: - A: Head is incorrect as it is the right end of the pancreas, farther away from the spleen. - B: Neck is incorrect as it is the narrow portion between the head and body, not near the spleen. - C: Body is incorrect as it is the central and longest part of the pancreas, not near the spleen. - D: Tail is correct as it is the left end of the pancreas, nearest to the hilum of the spleen.

Correct Answer: A

Rationale: Rationale: 1. T3, T4, and calcitonin are hormones secreted by the thyroid gland. 2. Thyroid gland is responsible for producing and releasing these hormones. 3. T3 and T4 regulate metabolism, while calcitonin helps regulate calcium levels. 4. Parathyroid glands secrete parathyroid hormone, not T3, T4, or calcitonin. 5. These hormones are not secreted in response to declining plasma levels of calcium. 6. T3, T4, and calcitonin are not steroids, they are peptide hormones. Therefore, the correct answer is A.

Correct Answer: A

Rationale: Step-by-step rationale: 1. The adrenal cortex is the outer layer of the adrenal gland that produces steroid hormones. 2. ACTH (adrenocorticotropic hormone) stimulates the adrenal cortex to secrete cortisol and aldosterone. 3. Therefore, the adrenal cortex is the target gland of ACTH, making choice A correct. Summary: A. Correct - The adrenal cortex is the target gland of ACTH. B. Incorrect - The adrenal medulla secretes catecholamines (e.g., adrenaline, noradrenaline). C. Incorrect - The sympathetic nervous system is responsible for the fight-or-flight response, not the adrenal cortex. D. Incorrect - ADH (antidiuretic hormone) and oxytocin are produced by the hypothalamus and released by the posterior pituitary gland, not the adrenal cortex.

Correct Answer: B

Rationale: The correct answer is B: Portal capillaries. The hypothalamus and adenohypophysis are connected by a system of blood vessels called the hypothalamic-pituitary portal system, which includes portal capillaries. These capillaries carry releasing and inhibiting hormones from the hypothalamus to the adenohypophysis to regulate the secretion of pituitary hormones. The other choices are incorrect because: A: Islets of Langerhans are clusters of cells in the pancreas involved in insulin and glucagon production, not connected to the hypothalamus or adenohypophysis. C: The corpus callosum is a structure that connects the two cerebral hemispheres and is not related to the hypothalamus or adenohypophysis. D: The medulla oblongata is part of the brainstem responsible for autonomic functions and is not involved in connecting the hypothalamus and adenohypophysis.

Correct Answer: C

Rationale: Step-by-step rationale: 1. Hypocalcemic tetany is associated with low levels of calcium in the blood. 2. Parathyroid hormone (PTH) plays a crucial role in calcium regulation. 3. A deficiency of PTH can lead to decreased calcium levels, causing tetany. 4. Therefore, choice C is correct as hypocalcemic tetany may be caused by a deficiency of PTH. Summary: A: Incorrect. Hypocalcemic tetany leads to muscle spasms, not flaccid paralysis. B: Incorrect. Curare blockade affects neuromuscular transmission, not calcium levels. D: Incorrect. Insulin deficiency is associated with hyperglycemia, not hypocalcemia leading to tetany.