HESI A2
HESI A2 Anatomy and Physiology Practice Test
1. Which organ system is primarily responsible for regulating electrolytes?
- A. The endocrine system
- B. The urinary system
- C. The lymphatic system
- D. The nervous system
Correct answer: B
Rationale: The urinary system, specifically the kidneys, is primarily responsible for regulating electrolytes in the body by filtering and excreting excess electrolytes, such as sodium, potassium, and chloride, through urine. The kidneys play a crucial role in maintaining the body's electrolyte balance, which is essential for various bodily functions and overall health. The endocrine system regulates hormones, the lymphatic system is involved in immunity, and the nervous system controls communication in the body. Therefore, the correct answer is B, the urinary system, as it directly handles electrolyte regulation by adjusting their excretion levels.
2. What is the first step in pulmonary circulation?
- A. Blood moves toward the heart through the pulmonary veins.
- B. The pulmonary artery carries blood from the heart to the lungs.
- C. Carbon dioxide is exchanged for oxygen.
- D. Oxygenated blood moves through the aorta.
Correct answer: B
Rationale: The correct answer is B: The pulmonary artery carries blood from the heart to the lungs. The first step in pulmonary circulation involves the right ventricle of the heart pumping deoxygenated blood into the pulmonary artery. The pulmonary artery then carries this deoxygenated blood from the heart to the lungs for oxygenation. This step is crucial for the exchange of carbon dioxide for oxygen to occur in the lungs, facilitating the oxygenation of blood. Choices A, C, and D are incorrect because they do not represent the initial step in pulmonary circulation. Option A refers to blood moving away from the heart, option C describes the gas exchange process that occurs in the lungs but not as the first step, and option D mentions oxygenated blood moving through the aorta, which happens after oxygenation in the lungs.
3. Which hormone is responsible for regulating the sleep-wake cycle?
- A. Melatonin
- B. Thyroxine
- C. Insulin
- D. Cortisol
Correct answer: A
Rationale: Melatonin, produced by the pineal gland, regulates the sleep-wake cycle by responding to light and darkness in the environment. It plays a crucial role in signaling the body when it's time to sleep and wake up, helping to establish and maintain a healthy circadian rhythm. Thyroxine, Insulin, and Cortisol do not directly regulate the sleep-wake cycle, making them incorrect choices for this question.
4. Which vitamin is necessary for the formation of collagen?
- A. Vitamin A
- B. Vitamin C
- C. Vitamin D
- D. Vitamin E
Correct answer: B
Rationale: Vitamin C is essential for the synthesis of collagen, a crucial protein that plays a significant role in maintaining the structural integrity of skin, blood vessels, and bones. Collagen is responsible for the strength, elasticity, and firmness of these tissues. Without sufficient vitamin C, the body cannot form collagen properly, leading to various health issues like scurvy, impaired wound healing, and fragile blood vessels. Choices A, C, and D are incorrect. Vitamin A plays a role in vision, immune function, and skin health. Vitamin D is crucial for bone health and immune function, while Vitamin E is an antioxidant that helps protect cells from damage.
5. Which part of the nervous system includes the femoral, radial, and ulnar nerves?
- A. Somatic
- B. Autonomic
- C. Sympathetic
- D. Parasympathetic
Correct answer: A
Rationale: The correct answer is A: Somatic. The femoral, radial, and ulnar nerves are all part of the somatic nervous system, responsible for controlling voluntary movements and sensory input. These nerves innervate muscles and skin throughout the body, allowing conscious control of movements and sensations. The somatic nervous system is distinct from the autonomic nervous system, which regulates involuntary bodily functions. Choices B, C, and D are incorrect because the autonomic nervous system (B) is responsible for involuntary functions, while the sympathetic (C) and parasympathetic (D) divisions are subdivisions of the autonomic nervous system, not the somatic nervous system.
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