HESI A2
HESI A2 Anatomy and Physiology Quizlet 2024
1. Which organ system is primarily responsible for preventing water loss?
- A. The nervous system
- B. The integumentary system
- C. The lymphatic system
- D. The urinary system
Correct answer: B
Rationale: The correct answer is B: The integumentary system. The integumentary system, which includes the skin, is primarily responsible for preventing water loss from the body. The skin acts as a barrier that helps regulate moisture and prevent excessive water loss through a process known as transepidermal water loss. The nervous system (choice A) is responsible for transmitting signals throughout the body, the lymphatic system (choice C) is responsible for the immune response and fluid balance, and the urinary system (choice D) is responsible for filtering blood and producing urine, but they do not primarily prevent water loss like the integumentary system.
2. What is the primary function of the cardiovascular system?
- A. To pump blood throughout the body
- B. To deliver nutrients to tissues
- C. To regulate body temperature
- D. To protect the body from infection
Correct answer: A
Rationale: The primary function of the cardiovascular system is to pump blood throughout the body, ensuring that oxygen and nutrients are delivered to tissues while removing waste products. This circulation is essential for maintaining overall health and proper functioning of the body's cells and organs. Choices B, C, and D are incorrect because while the cardiovascular system does deliver nutrients to tissues indirectly by transporting them in the blood, regulating body temperature is primarily the role of the endocrine and nervous systems, and protecting the body from infection is the main function of the immune system.
3. Which type of joint allows for rotational movement?
- A. Hinge joint
- B. Pivot joint
- C. Ball and socket joint
- D. Saddle joint
Correct answer: B
Rationale: A pivot joint, such as the one found in the neck, allows for rotational movement, enabling the head to turn from side to side. This type of joint provides a specific axis of rotation, allowing for a turning motion around that axis. Choice A, the hinge joint, primarily allows movement in one plane, like the elbow joint's flexion and extension. Choice C, the ball and socket joint, allows for a wide range of motion in multiple directions, but it is not primarily known for rotational movement. Choice D, the saddle joint, allows for movements like bending, straightening, and limited rotation, but it is not primarily designed for rotational movement like the pivot joint.
4. Which of the following structures regulates the transport of substances in and out of a cell?
- A. Nucleus
- B. Cell membrane
- C. Cytoplasm
- D. Mitochondria
Correct answer: B
Rationale: The cell membrane, also known as the plasma membrane, is responsible for regulating the transport of substances in and out of the cell. It acts as a selective barrier, allowing the passage of certain molecules while restricting others. This selective permeability helps maintain homeostasis within the cell by controlling the movement of essential substances like nutrients and waste products. The nucleus (Choice A) is the organelle that houses the cell's genetic material and is not directly involved in regulating substance transport. Cytoplasm (Choice C) is the gel-like substance that fills the cell and does not play a direct role in regulating substance transport. Mitochondria (Choice D) are responsible for energy production in the cell through cellular respiration and are not primarily involved in substance transport.
5. Which hormone is involved in regulating the sleep-wake cycle?
- A. Insulin
- B. Melatonin
- C. Cortisol
- D. Thyroxine
Correct answer: B
Rationale: The correct answer is B: Melatonin. Melatonin, produced by the pineal gland, is the hormone involved in regulating the sleep-wake cycle. It plays a crucial role in signaling the body that it is time to sleep and is influenced by light exposure. Melatonin levels typically rise in the evening, promoting sleep, and decrease in the morning, helping in waking up. Choice A, Insulin, is involved in regulating blood sugar levels, not the sleep-wake cycle. Choice C, Cortisol, is a stress hormone that helps regulate metabolism and immune response but is not primarily involved in the sleep-wake cycle. Choice D, Thyroxine, is a hormone produced by the thyroid gland that regulates metabolism, growth, and development, but it is not directly involved in regulating the sleep-wake cycle.
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