HESI A2 Anatomy and Physiology Practice Test 2023

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: A

Rationale: The correct answer is A. The medulla oblongata controls vital functions such as breathing and heart rate. It contains centers that regulate the rate and depth of breathing as well as the heartbeat. This is crucial for maintaining homeostasis and ensuring oxygen is delivered to tissues. Other choices are incorrect because the medulla oblongata is not responsible for regulating body temperature (B), coordinating voluntary movements (C), or processing sensory information (D). These functions are associated with other regions of the brain such as the hypothalamus, cerebellum, and cerebral cortex, respectively.

Correct Answer: B

Rationale: The correct answer is B: To regulate metabolism and stress response. The adrenal glands produce hormones like cortisol and adrenaline, which play a crucial role in regulating metabolism and the body's response to stress. Insulin production is primarily done by the pancreas (not adrenal glands), fighting infections is the role of the immune system (not adrenal glands), and while the adrenal glands do play a role in blood pressure regulation, it is not their primary function.

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 primary function of red blood cells is transporting oxygen. Red blood cells contain hemoglobin, which binds to oxygen in the lungs and carries it to tissues throughout the body. This process is essential for cellular respiration and energy production. Clotting blood is primarily done by platelets, not red blood cells. Fighting infection is the role of white blood cells. Carrying hormones is mainly done by proteins such as albumin in the blood, not red blood cells. Therefore, the correct answer is B.