Anatomy and Physiology Hesi A2 Practice Test

Correct Answer: B

Rationale: The correct answer is B: Glomerulus. The glomerulus is a network of capillaries located within the Bowman's capsule in the nephron. It filters blood to form urine by allowing small molecules like water, ions, and waste products to pass through while retaining larger molecules like proteins and blood cells. The other choices, A (Nephron), C (Bowman's capsule), and D (Loop of Henle) are all parts of the nephron, which is the functional unit of the kidney. While the nephron as a whole is responsible for urine formation, the specific structure that filters blood to form urine is the glomerulus within the Bowman's capsule.

Correct Answer: B

Rationale: The correct answer is B: Vitamin A. Step 1: Vitamin A is essential for maintaining healthy skin as it promotes cell growth and repair. Step 2: Vitamin A is crucial for vision as it is a component of rhodopsin, a protein in the retina. Step 3: Vitamin C (choice A) is important for immune function and collagen production, not specifically skin or vision. Vitamin D (choice C) is essential for bone health, not skin or vision. Vitamin K (choice D) is important for blood clotting, not skin or vision.

Correct Answer: B

Rationale: The correct answer is B: To protect the body from infections. The immune system's main function is to defend the body against pathogens such as bacteria, viruses, and other harmful microorganisms. It does this by recognizing and attacking these invaders to prevent infections and maintain overall health. Choice A is incorrect as the immune system does not primarily produce hormones. Choice C is incorrect as waste removal is mainly carried out by the excretory system. Choice D is incorrect as regulating body temperature is primarily controlled by the thermoregulatory system, not the immune system.

Correct Answer: D

Rationale: Step-by-step rationale for why choice D (Parathyroid) is correct: 1. Parathyroid glands are not directly involved in the stress response. 2. When under stress, hypothalamus triggers the release of hormones from posterior pituitary and adrenal cortex. 3. Parathyroid regulates calcium levels, not stress hormones. 4. Choices A, B, and C are all directly involved in the stress response. In summary, the parathyroid gland is not a part of the stress response system, unlike the posterior pituitary, hypothalamus, and adrenal cortex.

Correct Answer: B

Rationale: The correct answer is B: Medulla oblongata. The medulla oblongata is located in the brainstem and is responsible for controlling vital functions such as breathing and heart rate. It contains the respiratory center that regulates breathing and the cardiac center that controls heart rate. The cerebrum (A) is involved in higher brain functions such as thinking and voluntary movements, not in controlling basic bodily functions. The cerebellum (C) is responsible for coordination and balance, not for regulating breathing or heart rate. The hypothalamus (D) plays a role in regulating body temperature, hunger, and thirst, but not specifically in controlling breathing and heart rate.