Nursing Elites

1. What is the main function of the lungs?

• A. To transport oxygen and nutrients throughout the body
• B. To coordinate movement and sensory information
• C. To filter waste products from the blood
• D. To exchange oxygen and carbon dioxide between the body and the environment

Correct answer: D

Rationale: The main function of the lungs is to exchange oxygen and carbon dioxide between the body and the environment. This process occurs through the alveoli in the lungs where oxygen from inhaled air enters the bloodstream, and carbon dioxide is removed from the bloodstream and exhaled. Option A is incorrect as the transportation of oxygen and nutrients throughout the body is primarily carried out by the circulatory system, not the lungs. Option B is incorrect as coordinating movement and sensory information is a function of the nervous system, not the lungs. Option C is incorrect as filtering waste products from the blood is primarily the role of the kidneys, not the lungs. Therefore, the correct answer is D.

2. Microfilaments and microtubules are both components of the cytoskeleton, but they have different functions. Which of these describes microfilaments?

• A. Provide structural support and shape
• B. Facilitate cell movement and contraction
• C. Form the mitotic spindle during cell division
• D. Transport materials within the cell

Correct answer: A

Rationale: Microfilaments are thin, solid rods made of the protein actin and are primarily responsible for providing structural support to the cell and determining its shape. While they also play a role in cell movement, their main function is related to maintaining the structural integrity of the cell. Choice B, 'Facilitate cell movement and contraction,' describes microtubules, which are responsible for facilitating cell movement, providing structural support, and aiding in cell division. Choice C, 'Form the mitotic spindle during cell division,' specifically refers to the function of microtubules in forming the mitotic spindle. Choice D, 'Transport materials within the cell,' is characteristic of microtubules that are involved in intracellular transport of organelles and materials within the cell.

3. Which of the following is the MOST common symptom of angina pectoris, a condition related to insufficient blood flow to the heart?

• A. Fever and chills.
• B. Chest pain or discomfort.
• C. Sudden onset of severe shortness of breath.
• D. Numbness or tingling in the extremities.

Correct answer: B

Rationale: Chest pain or discomfort is the most common symptom of angina pectoris. This pain is often described as squeezing, pressure, heaviness, tightness, or pain in the chest. Fever and chills, sudden onset of severe shortness of breath, and numbness or tingling in the extremities are not typical symptoms of angina pectoris. The pain associated with angina is usually triggered by physical or emotional stress and typically subsides with rest or medication, distinguishing it from other conditions.

4. Which of the following units is used to express concentration as a mass of solute per unit volume of solution?

• A. Molality (m)
• B. Molarity (M)
• C. Weight percent (%)
• D. Parts per million (ppm)

Correct answer: A

Rationale: Molality (m) is the unit used to express concentration as a mass of solute per unit volume of solution. It is calculated by dividing the mass of solute in grams by the mass of the solvent in kilograms. Molality is preferred over molarity when there are large temperature variations as it is temperature-independent, making it a more accurate measure of concentration. Molarity (B) is the unit used to express concentration as moles of solute per liter of solution, weight percent (C) is the mass of solute per 100 parts of the total mass of the solution, and parts per million (D) is used to express very small concentrations where 1 ppm is equivalent to 1 mg of solute per liter of solution.

5. Which neurotransmitter is responsible for stimulating muscle contraction?

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

Correct answer: B

Rationale: Acetylcholine is the neurotransmitter responsible for stimulating muscle contraction at the neuromuscular junction. When an action potential reaches the end of a motor neuron, acetylcholine is released into the synaptic cleft and binds to receptors on the muscle cell membrane, leading to muscle contraction. Dopamine, serotonin, and norepinephrine are neurotransmitters that have different functions in the nervous system and are not directly involved in stimulating muscle contraction. Dopamine is involved in reward and pleasure pathways, serotonin regulates mood and behavior, and norepinephrine is involved in the 'fight or flight' response.

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