HESI A2 Anatomy and Physiology Practice Test 2023

Correct Answer: B

Rationale: The correct answer is B: Filtering blood to remove waste. The primary function of the kidneys is to filter blood and remove waste products, excess water, and electrolytes to form urine. This process helps maintain the body's fluid balance and eliminate toxins. Regulating blood pressure (A) is partially true, but not the primary function. Producing red blood cells (C) is done by the bone marrow, not the kidneys. Regulating electrolyte balance (D) is an important function of the kidneys, but not the primary one.

Correct Answer: C

Rationale: The correct answer is C: Appendix. The appendix is a part of the immune system as it contains lymphoid tissue that helps in immune responses. It plays a role in maintaining gut microbiota and fighting off infections. The other choices, heart, bronchi, and esophagus, are not directly involved in the immune system. The heart is responsible for pumping blood, the bronchi are air passages in the lungs, and the esophagus is a tube that connects the throat to the stomach. Therefore, the appendix is the only organ listed that is directly associated with the immune system.

Correct Answer: B

Rationale: The correct answer is B: Hippocampus. The hippocampus is a key brain region involved in memory formation due to its role in encoding, storing, and retrieving memories. It plays a crucial role in both short-term and long-term memory processes. Damage to the hippocampus can result in amnesia, further emphasizing its importance in memory formation. Incorrect choices: A: Cerebellum - Primarily involved in motor control and coordination. C: Brainstem - Regulates basic life functions such as breathing and heart rate. D: Frontal lobe - Responsible for executive functions, decision-making, and personality. While it plays a role in memory retrieval, it is not primarily involved in memory formation.

Correct Answer: B

Rationale: The correct answer is B: To fight infections. The immune system's primary function is to protect the body from harmful pathogens such as bacteria, viruses, and parasites. It does this by identifying and destroying these invaders to prevent infections and maintain overall health. Choices A, C, and D are incorrect because transporting oxygen is the role of the respiratory system, producing energy is the role of the metabolic system, and regulating body temperature is the role of the thermoregulatory system, not the immune system.

Correct Answer: B

Rationale: The correct answer is B: Insulin. The pancreas produces insulin to lower blood glucose levels by facilitating the uptake of glucose into cells for energy or storage. Glucagon (A) raises blood glucose levels, cortisol (C) is a stress hormone, and melatonin (D) regulates sleep cycles and has no direct impact on blood glucose levels. Insulin is the only hormone among the choices that specifically targets lowering blood glucose levels through its actions on glucose metabolism.