Anatomy HESI A2

Correct Answer: C

Rationale: Rationale: Prolactin is the hormone responsible for stimulating milk production in the breasts during lactation. It is produced by the pituitary gland. Norepinephrine is not involved in milk production. Antidiuretic hormone regulates water balance. Oxytocin is responsible for milk ejection, not production.

Correct Answer: B

Rationale: The correct answer is B: Iodine. Iodine is essential for the production of thyroid hormones, which are crucial for regulating metabolism and growth. Without enough iodine, the thyroid gland cannot function properly, leading to conditions like hypothyroidism or goiter. A: Manganese does not directly support thyroid function. C: Phosphorus is important for bone health and energy metabolism but not specifically for thyroid function. D: Zinc is involved in various physiological processes, but it is not as critical for thyroid function as iodine. In summary, iodine is the correct answer because it is specifically required for the synthesis of thyroid hormones, while the other choices do not play a direct role in supporting thyroid function.

Correct Answer: C

Rationale: The correct answer is C because body cells recognizing a pathogen represent an adaptive immune response, which is a specific and targeted defense mechanism. In contrast, choices A, B, and D are all examples of innate immune defenses that provide a nonspecific barrier against pathogens without the need for prior exposure. A: A low pH in the stomach creates an acidic environment that can kill many pathogens. B: Cilia in the trachea help to trap and remove inhaled pathogens. D: Mucus in the nasal cavity acts as a physical barrier to trap and remove pathogens. Therefore, choice C stands out as it involves a more sophisticated and specific defense mechanism compared to the other choices.

Correct Answer: A

Rationale: The correct answer is A: To break down proteins. Pepsin is an enzyme produced in the stomach that specifically functions to break down proteins into smaller peptides. This process is crucial for the digestion and absorption of proteins in the body. Pepsin works optimally in the acidic environment of the stomach. Choices B, C, and D are incorrect because pepsin is not involved in breaking down starches, emulsifying fats and oils, or absorbing water and nutrients. Other enzymes like amylase are responsible for breaking down starches, bile helps emulsify fats, and various enzymes and mechanisms are involved in water and nutrient absorption in the digestive system.

Correct Answer: C

Rationale: The correct answer is C: Along the sciatic nerve. A herniated lumbar disc can compress the sciatic nerve, causing pain that radiates down the leg (sciatica). The sciatic nerve is a major nerve that originates from the lower back, so compression at this level can lead to symptoms in the buttocks, thigh, or lower leg. Choices A and D are incorrect because the radial nerve and tibial nerve are not typically associated with lumbar disc herniation. Choice B is incorrect because a herniated disc does not occur within the spinal cord itself, but rather in the spinal canal where it can impinge on nearby nerves such as the sciatic nerve.