HESI A2 Anatomy and Physiology Practice Exam

Correct Answer: B

Rationale: The correct answer is B: proximal. The shoulder is proximal to the elbow because "proximal" refers to a structure being closer to the point of attachment or origin, which is the case for the shoulder in relation to the elbow. The other choices are incorrect because: A: Posterior refers to the back side, not the proximity. C: Distal means farther away from the point of attachment, which is opposite to the relationship between the shoulder and elbow. D: Medial refers to being closer to the midline of the body, not the point of attachment in this context.

Correct Answer: D

Rationale: The correct answer is D: Melatonin. The pineal gland is responsible for producing melatonin, a hormone that regulates the sleep-wake cycle. It is released in response to darkness, helping to signal the body that it is time to sleep. Corticosteroid (A) is produced by the adrenal glands, oxytocin (B) is produced by the hypothalamus and released by the pituitary gland, and prolactin (C) is produced by the pituitary gland. Therefore, the correct answer is D as it directly relates to the function of the pineal gland.

Correct Answer: B

Rationale: The parathyroid hormone regulates calcium levels in the body. It does so by increasing the release of calcium from bones, promoting calcium absorption in the intestines, and reducing calcium excretion by the kidneys. This is crucial for maintaining proper bone density and nerve function. Choice A (Magnesium) is incorrect because the parathyroid hormone does not directly regulate magnesium levels. Choice C (Calcitonin) is incorrect because calcitonin, produced by the thyroid gland, works in opposition to parathyroid hormone to lower blood calcium levels. Choice D (Glucocorticoids) is incorrect because these hormones, produced by the adrenal glands, are involved in metabolism, immune response, and stress regulation, but not in calcium regulation.

Correct Answer: A

Rationale: The correct answer is A: iris and lens. The anterior chamber of the eye is the space between the cornea (in front) and the iris and lens (behind). The cornea covers the front of the eye, and the iris is the colored part of the eye that controls the size of the pupil. The lens is located behind the iris and helps to focus light onto the retina at the back of the eye. Therefore, the correct placement of the anterior chamber is between the iris and lens. The other choices are incorrect because the lens and retina are not adjacent to each other in the eye, the cornea and iris are both in front of the anterior chamber, and the retina and optic nerve are located at the back of the eye, behind the lens.

Correct Answer: A

Rationale: The correct answer is A: The endocrine system. The endocrine system produces hormones such as cortisol and adrenaline, which play a crucial role in the body's stress response. These hormones help regulate heart rate, metabolism, and other physiological responses to stress. The digestive system (B), lymphatic system (C), and respiratory system (D) do not have primary roles in controlling stress. The digestive system is responsible for breaking down food, the lymphatic system helps with immunity, and the respiratory system is involved in breathing.