Nursing Elites

1. What is the function of the myelin sheath in a neuron?

• A. To transmit electrical impulses
• B. To insulate and speed up electrical signals
• C. To produce neurotransmitters
• D. To protect the neuron from damage

Correct answer: B

Rationale: The myelin sheath serves to insulate neurons and accelerate the transmission of electrical signals along the axon. This insulation helps in the efficient conduction of nerve impulses by preventing signal loss or leakage. Choice A is incorrect because the myelin sheath does not transmit electrical impulses itself but rather helps in the conduction. Choice C is incorrect as the myelin sheath is not responsible for producing neurotransmitters. Choice D is also incorrect as the primary function of the myelin sheath is not to protect the neuron from damage. Therefore, the correct answer is B, as it accurately describes the function of the myelin sheath in a neuron.

2. Which structure in the lungs is the site of gas exchange?

• A. Trachea
• B. Alveoli
• C. Bronchioles
• D. Diaphragm

Correct answer: B

Rationale: The correct answer is B: Alveoli. Alveoli are tiny air sacs in the lungs where gas exchange occurs. Oxygen from inhaled air diffuses into the bloodstream, while carbon dioxide from the blood is released into the alveoli to be exhaled. The trachea (Choice A) is the windpipe that carries air to and from the lungs, but it is not involved in gas exchange. Bronchioles (Choice C) are small air passages within the lungs that branch off from the bronchi, leading air to the alveoli but not directly involved in gas exchange. The diaphragm (Choice D) is a muscle below the lungs that helps in breathing by expanding and contracting the chest cavity, but it is not the site of gas exchange.

3. What is the process of removing waste products from the cell called?

• A. Exocytosis
• B. Endocytosis
• C. Phagocytosis
• D. Pinocytosis

Correct answer: A

Rationale: A) Exocytosis is the process by which cells expel waste products or other substances by fusing a vesicle containing the waste with the cell membrane, releasing its contents outside the cell. This process is essential for maintaining cellular homeostasis by removing waste products from the cell. B) Endocytosis is the process by which cells take in substances by engulfing them in a vesicle formed from the cell membrane. This process is the opposite of exocytosis and is used to bring substances into the cell. C) Phagocytosis is a type of endocytosis where cells engulf solid particles or other cells to form a vesicle called a phagosome. This process is used by immune cells to engulf and destroy pathogens. D) Pinocytosis is a type of endocytosis where cells engulf fluids and dissolved solutes. This process allows cells to take in nutrients.

4. Chromatids divide into identical chromosomes and migrate to opposite ends of the cell in which of the following phases of mitosis?

• A. metaphase
• B. anaphase
• C. prophase
• D. telophase

Correct answer: B

Rationale: During anaphase of mitosis, the sister chromatids detach from each other and migrate to opposite poles of the cell. This process ensures that each daughter cell ultimately receives an identical set of chromosomes, as the chromatids separate and become individual chromosomes again. This is a crucial step in ensuring accurate distribution of genetic material during cell division. In metaphase, the chromosomes align at the cell's equator but do not separate yet. Prophase is the phase where chromatin condenses into chromosomes and the nuclear envelope breaks down. Telophase is the final phase where the nuclear envelope reforms around the separated chromosomes.

5. Which of the following organs is part of the central nervous system?

• A. Heart
• B. Brain
• C. Liver
• D. Lungs

Correct answer: B

Rationale: The correct answer is B: Brain. The brain is a vital organ that is part of the central nervous system, along with the spinal cord. It plays a crucial role in processing information, controlling body functions, and coordinating responses to stimuli. The heart, liver, and lungs are not part of the central nervous system; they belong to the cardiovascular and respiratory systems, respectively. The heart is part of the cardiovascular system, responsible for pumping blood throughout the body. The liver is part of the digestive system, involved in processes like detoxification and metabolism. The lungs are part of the respiratory system, facilitating the exchange of oxygen and carbon dioxide during breathing.

Similar Questions