Nursing Elites

1. Which of the following is NOT a function of the cilia lining the respiratory tract?

• A. Trapping inhaled dust and debris
• B. Moistening inhaled air
• C. Producing mucus
• D. Propelling mucus upwards towards the throat

Correct answer: B

Rationale: The correct answer is B: Moistening inhaled air. The cilia lining the respiratory tract primarily function to trap inhaled dust and debris, produce mucus, and propel the mucus upwards towards the throat for removal. Moistening inhaled air is primarily done by the mucous membranes in the nasal passages, which contain blood vessels that help warm and humidify the air as it passes through the nasal cavity. Therefore, the function of moistening inhaled air is not directly associated with the cilia in the respiratory tract, making it the correct choice in this scenario. Choices A, C, and D are incorrect as they are all functions carried out by the cilia in the respiratory tract.

2. A ball is thrown upwards. Which of the following statements is TRUE about its potential energy and kinetic energy at the peak of its trajectory?

• A. Both potential and kinetic energy are zero.
• B. Potential energy is maximum and kinetic energy is minimum.
• C. Potential energy is minimum and kinetic energy is maximum.
• D. Both potential and kinetic energy remain constant.

Correct answer: B

Rationale: At the peak of its trajectory, the ball momentarily stops moving before falling back down. This means its kinetic energy is at a minimum because it has come to a stop. At the same time, its potential energy is at a maximum because it is at the highest point in its trajectory, where it has the most potential to fall and convert that potential energy into kinetic energy as it descends. Choice A is incorrect because at the peak, the ball still has potential energy due to its height. Choice C is incorrect because kinetic energy is at a minimum when the ball is momentarily at rest. Choice D is incorrect because the energy conversion between potential and kinetic energy occurs at different points in the trajectory.

3. 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.

4. Which of the following types of muscles is found in the walls of hollow organs?

• A. Cardiac
• B. Smooth
• C. Skeletal
• D. Voluntary

Correct answer: B

Rationale: Smooth muscles are the correct answer as they are found in the walls of hollow organs such as the intestines and blood vessels. Cardiac muscles are specifically found in the heart and are responsible for its contractions. Skeletal muscles are attached to bones and control voluntary movements. Voluntary muscles are under conscious control, but this term is not a specific type of muscle like smooth, cardiac, or skeletal muscles.

5. Which of the following is an example of an organ?

• A. Skin
• B. Neuron
• C. Brainstem
• D. DNA

Correct answer: A

Rationale: The correct answer is A, 'Skin.' The skin is the largest organ in the human body and consists of multiple tissue types working together to perform various functions such as protection, sensation, and temperature regulation. Choice B, 'Neuron,' is a specialized cell in the nervous system and not an organ. Choice C, 'Brainstem,' is a part of the central nervous system composed of nerve tissues but is not an organ on its own. Choice D, 'DNA,' is a molecule that carries genetic instructions, not an organ.

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