HESI A2 Anatomy and Physiology Practice Exam

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: 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: Step-by-step rationale: 1. Selenium is an essential mineral known for its antioxidant properties. 2. Antioxidants help neutralize free radicals that can damage cells and lead to various health issues. 3. Selenium specifically plays a crucial role in protecting cells from oxidative stress. 4. Calcium, Sulfur, and Iron are important minerals for various bodily functions but are not primarily known for their antioxidant properties. In summary: - A: Selenium is correct due to its antioxidant properties. - B: Calcium is important for bone health, not specifically an antioxidant. - C: Sulfur is needed for protein synthesis, not primarily an antioxidant. - D: Iron is essential for oxygen transport, not primarily an antioxidant.

Correct Answer: C

Rationale: Step-by-step rationale for why the correct answer is C (Columnar Epithelium): 1. Pillar-shaped cells indicate tall, elongated cells. 2. Columnar epithelium consists of tall cells with nuclei located near the base. 3. This tissue is specialized for absorption and secretion. 4. Tight arrangement suggests a protective and selective barrier. Summary: A: Squamous epithelium has flat cells, not pillar-shaped. B: Cuboidal epithelium has cube-shaped cells, not pillar-shaped. D: Transitional epithelium is found in urinary system, not pillar-shaped cells.

Correct Answer: A

Rationale: The correct answer is A: Vitamin B1, which is another name for thiamine. Thiamine is essential for energy metabolism and nerve function. Vitamin B2 (choice B) is riboflavin, Vitamin B6 (choice C) is pyridoxine, and Vitamin D (choice D) is important for bone health. Thiamine deficiency can lead to serious conditions like beriberi, making it crucial for overall health.