Nursing Elites

1. Muscles that work in opposition to each other, producing opposing movements, are called:

• A. Synergists
• B. Antagonists
• C. Agonists
• D. Fixators

Correct answer: B

Rationale: The correct answer is B: 'Antagonists.' Antagonistic muscles are pairs of muscles that work in opposition to each other to produce opposing movements around a joint. For example, the biceps and triceps in the arm act as antagonists - when the biceps contract to bend the elbow, the triceps relax, and vice versa. Synergists (A) are muscles that work together to create a movement, agonists (C) are primary muscles responsible for generating movement, and fixators (D) are muscles that stabilize joints to allow other movements to occur. Understanding the roles of antagonistic muscles is crucial in biomechanics and exercise science.

2. A car skids on a wet road. What is the main force preventing the car from stopping?

• A. Friction
• B. Gravitational force
• C. Normal force from the road
• D. Air resistance

Correct answer: A

Rationale: Friction opposes the motion of the car, trying to bring it to a stop. However, due to the wet surface, the friction force is not enough to overcome the car's inertia.

3. What is the valve that prevents blood from flowing back from the left ventricle into the left atrium?

• A. Tricuspid valve
• B. Mitral valve
• C. Aortic valve
• D. Pulmonic valve

Correct answer: B

Rationale: The correct answer is B: Mitral valve. The mitral valve, also known as the bicuspid valve, is located between the left atrium and the left ventricle. Its primary function is to prevent the backflow of blood from the left ventricle into the left atrium during ventricular contraction. The tricuspid valve is located between the right atrium and right ventricle, the aortic valve is located between the left ventricle and the aorta, and the pulmonic valve is located between the right ventricle and the pulmonary artery. Therefore, the mitral valve is specifically responsible for preventing backflow in the left side of the heart, making it the correct answer.

4. What defines the period of a wave?

• A. The number of waves passing a point per unit time
• B. The distance between two adjacent crests or troughs
• C. The time it takes for one complete wave cycle to pass a point
• D. The maximum displacement of particles in a medium due to the wave

Correct answer: C

Rationale: The period of a wave is defined as the time it takes for one complete wave cycle to pass a point. It is typically measured in seconds and is inversely related to the frequency of the wave. The period is not related to the number of waves passing a point per unit time (A), the distance between two adjacent crests or troughs (B), or the maximum displacement of particles in a medium due to the wave (D).

5. Delta waves, associated with deep sleep, exhibit what frequency range?

• A. 0.5-4 Hz
• B. 4-8 Hz
• C. 8-13 Hz
• D. 13-30 Hz

Correct answer: A

Rationale: Delta waves are slow brainwaves that are typically associated with deep sleep stages, such as stages 3 and 4 of non-REM sleep. These waves have a frequency range of 0.5-4 Hz, making option A the correct answer. During deep sleep, the brain slows down significantly, and delta waves are prominent on an electroencephalogram (EEG). The frequency range of 4-8 Hz corresponds to theta waves, which are more commonly observed during light sleep or drowsiness. Alpha waves fall within the 8-13 Hz range and are typically seen when an individual is awake but relaxed. Beta waves, ranging from 13-30 Hz, are associated with alertness and active thinking. Therefore, option A is the correct choice for delta waves, reflecting their slow frequency characteristic during deep sleep.

6. Which element is used in fire extinguishers to smother flames by displacing oxygen?

• A. Nitrogen
• B. Carbon dioxide
• C. Helium
• D. Argon

Correct answer: B

Rationale: Carbon dioxide extinguishes flames by depriving them of oxygen, preventing the chemical reaction that sustains the fire.

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