Nursing Elites

1. 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.

2. Which of the following is a function of the liver?

• A. Producing digestive enzymes
• B. Storing bile
• C. Filtering waste products from the blood
• D. Transporting nutrients to cells

Correct answer: B

Rationale: The correct function of the liver is to store bile. Bile is produced in the liver and stored in the gallbladder until it is needed to aid in the digestion of fats. While the liver does produce bile, its primary role is to store and release it. Choices A, C, and D are incorrect. Producing digestive enzymes is mainly the function of the pancreas, filtering waste products from the blood is primarily done by the kidneys, and transporting nutrients to cells is typically associated with the circulatory system rather than the liver.

3. Which neurotransmitter is associated with mood regulation, sleep, and appetite?

• A. Acetylcholine
• B. Dopamine
• C. Serotonin
• D. GABA (Gamma-aminobutyric acid)

Correct answer: C

Rationale: The correct answer is C: Serotonin. Serotonin is a neurotransmitter that plays a crucial role in mood regulation, sleep, and appetite. It helps regulate emotions, mood, and behavior. Imbalances in serotonin levels have been associated with conditions such as depression, anxiety, and eating disorders. Choice A, Acetylcholine, is primarily involved in muscle control and memory functions. Choice B, Dopamine, is associated with reward, motivation, and motor control. Choice D, GABA (Gamma-aminobutyric acid), is an inhibitory neurotransmitter that helps reduce neuronal excitability and is not directly linked to mood regulation, sleep, or appetite.

4. What is a mutation?

• A. A change in the DNA sequence
• B. A type of protein
• C. A normal part of the DNA replication process
• D. A harmless variation in DNA

Correct answer: A

Rationale: A mutation is defined as a change in the DNA sequence, which can occur due to various factors such as errors during DNA replication, exposure to mutagens (e.g., chemicals, radiation), or spontaneous changes. These alterations can lead to modifications in the genetic information carried by an organism, resulting in effects that can range from harmless variations to causing genetic disorders or diseases. Mutations play a crucial role in genetic diversity and evolution. Choices B, C, and D are incorrect as they do not accurately define what a mutation is. Option B is incorrect because mutations are not a type of protein but rather changes in DNA. Option C is incorrect because while mutations can occur during DNA replication, they are not considered a 'normal' part of the process as they can lead to genetic variations. Option D is incorrect because mutations can have a wide range of effects and are not always harmless variations.

5. Which of the following are the blood vessels that transport blood away from the heart?

• A. arteries
• B. capillaries
• C. venules
• D. veins

Correct answer: A

Rationale: Arteries are blood vessels that carry oxygen-rich blood away from the heart to various parts of the body. Therefore, they are the vessels that transport blood away from the heart. Veins, on the other hand, transport blood back to the heart. Capillaries are tiny blood vessels where the exchange of nutrients and waste products occurs between blood and tissues, not vessels that transport blood to the heart. Venules are small veins that collect blood from capillaries and connect them to larger veins, rather than transport blood to the heart.

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