Anatomy HESI A2 Practice Test

Correct Answer: B

Rationale: The correct answer is B: Adrenal cortex. During stress, the adrenal cortex secretes cortisol and aldosterone, which help the body respond to stress. The parathyroid gland (A) regulates calcium levels, not stress hormones. The posterior pituitary gland (C) releases hormones like oxytocin and vasopressin, not stress hormones. The hypothalamus (D) plays a role in regulating the stress response by signaling the adrenal cortex to release stress hormones.

Correct Answer: D

Rationale: The correct answer is D because the liver is responsible for producing enzymes essential for metabolism. Enzymes are biological catalysts that facilitate chemical reactions involved in breaking down nutrients and creating energy. Storing glucose (A) is mainly done by the liver and muscles, secreting bile (B) is the primary function of the gallbladder, and detoxifying harmful substances (C) is also a crucial role of the liver but not directly related to metabolism.

Correct Answer: B

Rationale: The correct answer is B: Semicircular canals. These structures in the inner ear are responsible for detecting rotational movement and maintaining balance. The semicircular canals contain fluid that moves in response to head movements, stimulating hair cells that send signals to the brain about the body's position in space. A: The cochlea is responsible for hearing, not balance. C: Ossicles are tiny bones in the middle ear that transmit sound vibrations to the cochlea. D: The Eustachian tube helps equalize pressure in the middle ear and is not directly related to balance. In summary, the semicircular canals are crucial for maintaining balance by detecting rotational movements, while the other structures mentioned are primarily involved in hearing or pressure regulation.

Correct Answer: A

Rationale: The correct answer is A: Vitamin A. Vitamin A is essential for vision as it plays a crucial role in the function of the retina and helps maintain a healthy cornea. It is also important for skin health by promoting skin cell growth and repair. Vitamin C (B) is important for immune function and collagen synthesis, not specifically for vision or skin health. Vitamin D (C) is crucial for bone health and immune function. Vitamin E (D) is an antioxidant that helps protect cells from damage, but it is not specifically essential for vision or skin health.

Correct Answer: C

Rationale: The function of the alveoli in the lungs is to exchange gases. Oxygen from the inhaled air diffuses into the bloodstream, while carbon dioxide from the bloodstream diffuses into the alveoli to be exhaled. This exchange process is crucial for maintaining proper oxygen levels in the blood and removing carbon dioxide, a waste product. Option A is incorrect because the alveoli do not absorb oxygen but facilitate its exchange. Option B is incorrect because while the alveoli do remove carbon dioxide, their primary function is gas exchange. Option D is incorrect as the alveoli do not regulate blood pressure but are essential for gas exchange in the respiratory system.