Nursing Elites

1. Which cells myelinate neurons in the CNS?

• A. Schwann cells
• B. Astrocytes
• C. Microglia
• D. Oligodendrocytes

Correct answer: D

Rationale: The correct answer is D, Oligodendrocytes. Oligodendrocytes are responsible for myelinating neurons in the central nervous system (CNS). Schwann cells, found in the peripheral nervous system, are responsible for myelinating neurons there. Astrocytes support and maintain the neuronal environment, while microglia function as immune cells in the CNS, participating in immune responses and cellular debris clearance. Therefore, choices A, B, and C are incorrect for myelination of CNS neurons.

2. Which of the following statements is true about Noble gases?

• A. They are non-reactive.
• B. They are highly reactive.
• C. They have 8 valence electrons.
• D. They have 7 valence electrons.

Correct answer: A

Rationale: The correct answer is A: Noble gases are non-reactive because they have a full valence shell with 8 electrons, making them stable and unlikely to form chemical bonds with other elements. Choice B is incorrect because Noble gases are known for their inertness and lack of reactivity. Choice C is incorrect because Noble gases have 8 valence electrons, which is a key characteristic that contributes to their stability. Choice D is incorrect because Noble gases have 8 valence electrons, not 7.

3. What is the term for a solution that has exactly the same concentration of solute as another solution?

• A. Saturated solution
• B. Unsaturated solution
• C. Isotonic solution
• D. Concentrated solution

Correct answer: C

Rationale: An isotonic solution is a solution that has the same concentration of solute as another solution. When cells are placed in an isotonic solution, there is no net movement of water across the cell membrane, maintaining equilibrium. Choice A, a saturated solution, refers to a solution that contains the maximum amount of solute that can be dissolved at a given temperature. Choice B, an unsaturated solution, is a solution that contains less solute than a saturated solution under the same conditions. Choice D, a concentrated solution, is a solution with a high amount of solute compared to the solvent.

4. What is the main function of the large intestine?

• A. To absorb proteins
• B. To absorb water and form feces
• C. To produce enzymes for digestion
• D. To store fat

Correct answer: B

Rationale: The main function of the large intestine is to absorb water and form feces from waste material. Choice A is incorrect because the absorption of proteins primarily occurs in the small intestine. Choice C is incorrect as the production of enzymes for digestion mainly takes place in the pancreas and small intestine. Choice D is incorrect as the storage of fat is not a primary function of the large intestine.

5. Which of the following areas has the least amount of sweat glands?

• A. Back
• B. Palms
• C. Axilla
• D. Forehead

Correct answer: B

Rationale: The correct answer is B - Palms. The palms have the least amount of sweat glands compared to the other options listed. The back, axilla (armpits), and forehead are all areas with a higher concentration of sweat glands in the body. The palms have fewer sweat glands to minimize water loss and maintain a better grip for activities requiring precise and controlled movement. The back, axilla, and forehead have more sweat glands to assist in thermoregulation and cooling of the body, while the palms have fewer sweat glands for functional reasons related to grip and dexterity.

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