Nursing Elites

1. Which of the following is NOT a function of the endoplasmic reticulum (ER)?

• A. Synthesis of lipids (fats)
• B. Transport of materials within the cell
• C. Detoxification of harmful substances
• D. Breakdown of cellular waste products

Correct answer: C

Rationale: The correct answer is C: 'Detoxification of harmful substances.' The endoplasmic reticulum (ER) is responsible for synthesizing lipids (fats), transporting materials within the cell, and breaking down cellular waste products. However, detoxification of harmful substances is primarily carried out by the smooth endoplasmic reticulum (SER) where enzymes detoxify drugs and other harmful compounds. Therefore, C is the correct answer as it is not a primary function of the ER.

2. In a neutral atom, the number of electrons:

• A. Must be equal to the number of protons.
• B. Must be less than the number of protons.
• C. Must be greater than the number of neutrons.
• D. Can vary depending on the atom's temperature.

Correct answer: A

Rationale: Must be equal to the number of protons - For electrical neutrality, the positive charge of protons must be balanced by the negative charge of an equal number of electrons.

3. Coronary arteries are responsible for:

• A. Delivering oxygenated blood throughout the body.
• B. Supplying oxygenated blood to the heart muscle itself.
• C. Carrying deoxygenated blood back to the heart.
• D. Regulating blood pressure through vasoconstriction and vasodilation.

Correct answer: B

Rationale: The correct answer is B: 'Supplying oxygenated blood to the heart muscle itself.' Coronary arteries are specialized blood vessels that branch off the aorta and provide oxygenated blood to the heart muscle. This is crucial for the heart to function properly and maintain its own blood supply separate from the systemic circulation. The other options are incorrect because delivering oxygenated blood throughout the body is the role of the systemic circulation and not specific to coronary arteries. Carrying deoxygenated blood back to the heart is the function of veins, while regulating blood pressure through vasoconstriction and vasodilation is primarily controlled by arteries in general, not just the coronary arteries.

4. Balance the following redox reaction in acidic solution: I⁻ (aq) + Cr₂O₇²⁻ (aq) -> I₂ (aq) + Cr³⁺ (aq). Identify the oxidizing agent and reducing agent.

• A. I⁻ is oxidized, Crâ‚‚O₇²⁻ is reduced
• B. I⁻ is reduced, Crâ‚‚O₇²⁻ is oxidized.
• C. Both I⁻ and Crâ‚‚O₇²⁻ are oxidized.
• D. Both I⁻ and Crâ‚‚O₇²⁻ are reduced.

Correct answer: A

Rationale: . I⁻ loses an electron (oxidation), Cr₂O₇²⁻ gains electrons (reduction).

5. A patient needs to take 2 tablets for every 30 pounds of body weight. If they weigh 150 pounds, how many tablets should they take?

• A. 5
• B. 10
• C. 15
• D. 20

Correct answer: A

Rationale: Divide the patient's weight (150 pounds) by the ratio denominator (30 pounds/tablet) to get 5 tablets.

6. 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 correct answer is D, the Mitral valve. The Mitral valve, also known as the bicuspid valve, is located between the left atrium and left ventricle in the heart. It consists of two cusps that close tightly when the left ventricle contracts, preventing the backflow of blood into the left atrium. The aortic valve (option A) is responsible for preventing the backflow of blood from the aorta into the left ventricle, not the left atrium. The pulmonary valve (option B) prevents backflow from the pulmonary artery into the right ventricle, and the tricuspid valve (option C) prevents backflow from the right ventricle into the right atrium. Therefore, the Mitral valve is specifically responsible for preventing backflow from the left ventricle into the left atrium.

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