HESI A2 Anatomy and Physiology Practice Exam

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: B

Rationale: The correct answer is B: nervous system. The retinas belong to the nervous system as they are part of the sensory organs responsible for receiving and processing visual information. The retinas contain photoreceptor cells that convert light into electrical signals, which are then transmitted to the brain via the optic nerve for interpretation. The skeletal system (A) is responsible for providing support and protection for the body, the lymphatic system (C) is responsible for immune function and fluid balance, and the circulatory system (D) is responsible for transporting blood and nutrients throughout the body. Therefore, the retinas do not belong to these systems.

Correct Answer: D

Rationale: The correct answer is D, Integumentary system. Sebaceous glands are located in the skin, which is part of the integumentary system. These glands secrete sebum to lubricate and protect the skin. The endocrine system (choice A) regulates hormones, not sebum production. The digestive system (choice B) processes food, not related to sebaceous glands. The respiratory system (choice C) is responsible for gas exchange, not sebum secretion. Therefore, the integumentary system is the correct choice.

Correct Answer: C

Rationale: The correct answer is C: 26. The human foot consists of 26 bones, including the tarsal bones, metatarsal bones, and phalanges. Understanding human anatomy is crucial for healthcare professionals and students. Choice A (6) is too few for the complexity of the foot structure. Choice B (16) is close but doesn't account for all the bones in the foot. Choice D (36) is too high and likely includes bones from other parts of the body. Identifying the correct number of bones in the foot is essential for proper diagnosis and treatment of foot-related conditions.