Nursing Elites

1. Which neurotransmitter is involved in muscle movement?

• A. Dopamine
• B. Acetylcholine
• C. Serotonin
• D. GABA

Correct answer: B

Rationale: Acetylcholine is the neurotransmitter responsible for muscle movement. It is released from motor neurons at the neuromuscular junction and binds to receptors on muscle fibers, initiating muscle contraction. Dopamine, serotonin, and GABA serve different functions in the brain and body, such as regulating mood, sleep, and inhibitory signaling, respectively. Therefore, choices A, C, and D are incorrect in the context of muscle movement.

2. What is the primary function of the myelin sheath that surrounds some axons in the nervous system?

• A. To initiate nerve impulses
• B. To transmit sensory information
• C. To speed up the transmission of nerve impulses
• D. To connect neurons at synapses

Correct answer: C

Rationale: The primary function of the myelin sheath is to speed up the transmission of nerve impulses. The myelin sheath acts as an insulating layer around the axon, allowing for faster conduction of electrical impulses along the nerve fiber. This insulation prevents the electrical signal from dissipating or 'leaking' out, which helps in the rapid and efficient transmission of nerve impulses along the axon. Choice A is incorrect because the myelin sheath does not initiate nerve impulses; it helps in conducting them. Choice B is incorrect as the myelin sheath's main role is not in transmitting sensory information but rather in facilitating the transmission of nerve impulses. Choice D is incorrect because the myelin sheath's function is not to connect neurons at synapses; instead, it is primarily involved in enhancing the speed of nerve impulse transmission.

3. What effect does a catalyst have on a chemical reaction?

• A. It speeds up the reaction.
• B. It slows down the reaction.
• C. It makes a reaction go in reverse.
• D. It prevents a reaction from taking place.

Correct answer: A

Rationale: A catalyst is a substance that increases the rate of a chemical reaction without being consumed in the process. It works by providing an alternate pathway for the reaction to occur, lowering the activation energy needed for the reaction to proceed. As a result, more reactant molecules can overcome this energy barrier and participate in the reaction, leading to a faster overall reaction rate. This explanation contradicts choices B, C, and D as a catalyst does not slow down, reverse, or prevent a reaction; instead, it accelerates the reaction by facilitating a more efficient route for the reaction to take place. Therefore, the correct answer is that a catalyst speeds up the reaction.

4. Which of the following hormones regulates calcium levels in the blood?

• A. Insulin
• B. Parathyroid hormone
• C. Thyroid hormone
• D. Glucagon

Correct answer: B

Rationale: The correct answer is B, Parathyroid hormone. Parathyroid hormone plays a crucial role in regulating calcium levels in the blood by increasing calcium levels when they are too low. This hormone acts on the bones, kidneys, and intestines to ensure proper calcium balance in the body. Insulin (choice A) is involved in glucose metabolism, not calcium regulation. Thyroid hormone (choice C) primarily regulates metabolism, and while it indirectly influences calcium levels, it is not the primary regulator. Glucagon (choice D) is involved in increasing blood glucose levels, not calcium regulation.

5. Which of the following is NOT a major component of a healthy blood pressure reading?

• A. Systolic pressure (peak pressure during ventricular contraction)
• B. Diastolic pressure (pressure within arteries during ventricular relaxation)
• C. Pulse pressure (difference between systolic and diastolic pressure)
• D. Blood oxygen saturation levels. While blood oxygen levels are crucial for overall health, they are not directly reflected in a blood pressure reading.

Correct answer: D

Rationale: Blood oxygen saturation levels are essential for overall health but are not directly part of a blood pressure reading. A healthy blood pressure reading consists of systolic pressure, diastolic pressure, and pulse pressure. Systolic pressure represents the peak pressure during ventricular contraction, diastolic pressure reflects the pressure within arteries during ventricular relaxation, and pulse pressure is the difference between systolic and diastolic pressure. These components collectively provide information about the pressure variations within the arteries throughout the cardiac cycle phases, contributing to the assessment of cardiovascular health. Therefore, choice D, blood oxygen saturation levels, is not a major component of a healthy blood pressure reading and is the correct answer. Choices A, B, and C are major components of a healthy blood pressure reading and directly relate to the pressure variations within the arteries during different phases of the cardiac cycle.

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