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: Antagonist muscles are pairs of muscles that work in opposition to each other, producing opposing movements. When one muscle contracts, the other relaxes to allow the movement to occur smoothly. Synergists are muscles that work together to create a movement, not in opposition. Agonists are muscles primarily responsible for producing a specific movement, not opposing each other. Fixators are muscles that stabilize joints to allow other movements to take place, providing a stable base for muscle actions but do not produce opposing movements.

2. Which structure in the heart is responsible for preventing the backflow of blood from the left ventricle into the left atrium?

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

Correct answer: D

Rationale: The mitral valve, also known as the bicuspid valve, is located between the left atrium and the left ventricle of the heart. Its primary function is to prevent the backflow of blood from the left ventricle into the left atrium during ventricular contraction. The aortic valve (A) prevents the backflow of blood from the aorta into the left ventricle, the pulmonary valve (B) prevents the backflow of blood from the pulmonary artery into the right ventricle, and the tricuspid valve (C) prevents the backflow of blood from the right ventricle into the right atrium. Understanding the functions of these heart valves is crucial in maintaining proper blood flow through the heart and preventing regurgitation of blood into the wrong chambers.

3. Which hormone is responsible for lowering blood sugar levels?

• A. Glucagon
• B. Insulin
• C. Adrenaline
• D. Cortisol

Correct answer: B

Rationale: Insulin is the hormone responsible for lowering blood sugar levels. It is produced by the pancreas and facilitates the entry of glucose into cells, thereby reducing blood sugar levels. Glucagon, adrenaline, and cortisol have roles in increasing blood sugar levels through various mechanisms. Glucagon raises blood sugar levels by stimulating the liver to release stored glucose, adrenaline increases blood sugar in fight-or-flight responses, and cortisol raises blood sugar levels as part of the stress response. Therefore, in the context of lowering blood sugar levels, insulin is the correct answer.

4. DNA has both a 'sense' and 'antisense' strand. What is true about the antisense strand?

• A. It runs 5' to 3'.
• B. It runs 3' to 5'.
• C. It is used in replication.
• D. It is the direction DNA is stored.

Correct answer: B

Rationale: The correct answer is B: 'It runs 3' to 5'. The antisense strand runs in the 3' to 5' direction, complementing the sense strand. Choice A is incorrect as the antisense strand runs in the opposite direction, which is 3' to 5'. Choice C is incorrect because the antisense strand is not directly involved in replication. Choice D is incorrect as the direction DNA is stored is not determined by the antisense strand.

5. Which organ in the body is responsible for filtering toxins from the blood?

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

Correct answer: B

Rationale: The liver is the organ responsible for filtering toxins from the blood. It plays a crucial role in detoxification by processing and eliminating harmful substances from the body. The kidneys primarily filter waste and excess substances from the blood to form urine, while the heart pumps blood throughout the body and the lungs facilitate gas exchange by oxygenating blood. Therefore, the correct answer is the liver as it is specifically involved in detoxifying the blood.

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