HESI A2 Anatomy and Physiology Practice Exam

Correct Answer: A

Rationale: Primary peristalsis occurs in the esophagus. This process involves coordinated muscle contractions that push food from the mouth to the stomach. The esophagus contains smooth muscles that contract rhythmically to propel food downwards. In contrast, the stomach's main function is to mix and churn food with gastric juices, not conduct peristalsis. The nervous system plays a role in regulating peristalsis but is not the location where it occurs. The small intestine is primarily involved in digestion and absorption of nutrients, not peristalsis. Therefore, the correct answer is A, as the esophagus is where primary peristalsis takes place.

Correct Answer: D

Rationale: The correct answer is D, Achilles tendon, as it is a posterior feature of the human leg. The Achilles tendon is located at the back of the ankle, connecting the calf muscles to the heel bone. This tendon is crucial for various movements like walking, running, and jumping. Rationale: 1. The Achilles tendon is a well-known structure located at the posterior aspect of the leg. 2. It plays a vital role in the functioning of the lower leg muscles. 3. The other choices (A: Patella, B: Quadriceps sartorius, C: Triceps brachii) are not located at the posterior aspect of the leg and are not directly related to the function of the lower leg muscles.

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: Tendon and possibly ligament. In a rotator cuff tear, the structures that are typically torn are the tendons of the rotator cuff muscles, particularly the supraspinatus tendon. The rotator cuff is composed of muscles and tendons, not ligaments. While it is possible for some ligaments to be involved in severe cases, the primary structures affected are the tendons. Choice B is incorrect because muscles are not typically torn in a rotator cuff tear. Choice C is incorrect as ligaments are not the primary structures involved in a rotator cuff tear. Choice D is incorrect as it suggests that only the tendons are affected, whereas the tear commonly involves both tendons and possibly ligaments.

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.