Which of the following signals would affect local cells by releasing chemicals into the extracellular fluid?

Correct Answer: B

Rationale: The correct answer is B: paracrine. Paracrine signaling involves the release of signaling molecules into the extracellular fluid to affect nearby target cells. This type of signaling is localized and affects cells within close proximity. Autocrine signaling (A) involves cells releasing signals that act on themselves, endocrine signaling (C) involves signaling molecules being released into the bloodstream to affect distant target cells, and neural signaling (D) involves the transmission of signals through neurons. In this case, paracrine signaling specifically targets local cells by releasing chemicals into the extracellular fluid, making it the correct choice.

Correct Answer: C

Rationale: The left supra-renal vein drains into the left renal vein. This is because the left adrenal gland is located above the left kidney, and the left renal vein is responsible for draining blood from the left kidney and adjacent structures, including the left adrenal gland. Therefore, the correct answer is C. Incorrect options: A: The inferior vena cava receives blood from various veins in the body but not specifically from the left supra-renal vein. B: The inferior mesenteric vein drains the large intestine and does not receive blood from the left supra-renal vein. D: The superior mesenteric vein drains blood from the small intestine and does not receive blood from the left supra-renal vein. In summary, the left supra-renal vein drains into the left renal vein due to their anatomical proximity, making option C the correct answer.

Correct Answer: a

Rationale: The correct answer is A: Epimysium. Epimysium is the dense connective tissue layer that surrounds the entire muscle belly, providing structural support and protection. It separates the biceps femoris muscle from surrounding tissues. Perimysium (B) surrounds bundles of muscle fibers within the muscle belly, while endomysium (C) surrounds individual muscle fibers. Blood (D) is not a connective tissue layer but a fluid tissue responsible for transporting nutrients and waste products. Therefore, the epimysium is the correct choice as it specifically surrounds the biceps femoris muscle belly.

Correct Answer: D

Rationale: The correct answer is D because iodine-containing hormones, such as thyroid hormones, regulate the metabolic rate by influencing the body's energy production and utilization. TSH (choice A) is not an iodine-containing hormone but a pituitary hormone that stimulates the thyroid gland to produce thyroid hormones. Hypothalamus releasing hormones (choice B) are not iodine-containing hormones. Steroids (choice C) are a different class of hormones that do not contain iodine. In summary, choice D is correct as iodine-containing hormones play a crucial role in regulating metabolic rate, while the other choices are incorrect as they do not accurately describe this function.

Correct Answer: B

Rationale: The correct answer is B: cortisol, aldosterone, and testosterone. "Sugar, salt, and sex" refers to hormones produced by the adrenal glands. Cortisol regulates sugar metabolism, aldosterone regulates salt balance, and testosterone is involved in sexual characteristics. A: ACTH, TSH, and somatotropic hormone are hormones produced by the pituitary gland. C: Epinephrine, norepinephrine, and estrogen are not directly related to the terms given. D: Insulin, glucagon, and cortisol are involved in glucose regulation, but do not match the specific terms provided.