Nursing Elites

1. Which of the following constituents of blood is a biconcave disc that is round and flat without a nucleus?

• A. Plasma
• B. Platelet
• C. RBC
• D. WBC

Correct answer: C

Rationale: The correct answer is C, RBC (Red Blood Cell). Red blood cells are biconcave discs that lack a nucleus, allowing them to carry oxygen efficiently. Plasma (A) is the liquid component of blood that carries various substances. Platelets (B) are cell fragments important for blood clotting. White blood cells (WBCs) (D) are part of the immune system and have a nucleus.

2. Which of the following vessels is responsible for pumping oxygenated blood to the body?

• A. Right ventricle
• B. Left ventricle
• C. Pulmonary artery
• D. Aorta

Correct answer: D

Rationale: The aorta is the correct answer because it is responsible for pumping oxygenated blood from the heart to the rest of the body. The aorta is the main artery that carries blood away from the heart and distributes it to all parts of the body, providing oxygen and nutrients to the tissues. Choices A, B, and C are incorrect. The right ventricle pumps deoxygenated blood to the lungs through the pulmonary artery, the left ventricle pumps oxygenated blood to the body through the aorta, and the pulmonary artery carries deoxygenated blood from the heart to the lungs for oxygenation.

3. In the reaction 2Na + 2H2O → 2NaOH + H2, what is the limiting reactant when 3 moles of sodium react with 2 moles of water?

• A. Na
• B. H2O
• C. NaOH
• D. H2

Correct answer: A

Rationale: The balanced chemical equation indicates that 2 moles of sodium react with 2 moles of water to yield 2 moles of sodium hydroxide and 1 mole of hydrogen gas. When 3 moles of sodium react with only 2 moles of water, sodium becomes the limiting reactant as it is present in excess compared to the available water molecules. This situation arises because not all sodium atoms can fully react with the limited amount of water, resulting in sodium being the limiting reactant in this specific case. Choice B (H2O), choice C (NaOH), and choice D (H2) are incorrect as they are not the limiting reactant in the given reaction scenario.

4. What is the fatty sheath that insulates some nerve fibers and speeds up signal transmission called?

• A. Myelin sheath
• B. Dura mater
• C. Pia mater
• D. Arachnoid mater

Correct answer: A

Rationale: The correct answer is A: Myelin sheath. The myelin sheath is a fatty layer that surrounds and insulates some nerve fibers, facilitating the rapid transmission of signals along the nerve fibers. Choices B, C, and D (Dura mater, Pia mater, and Arachnoid mater) are layers of the meninges, protective membranes that surround the brain and spinal cord. The primary function of the meninges is to protect and support the central nervous system, not to insulate nerve fibers for signal transmission.

5. Which of the following components of the human integumentary system is the deepest?

• A. Stratum basale
• B. Epidermis
• C. Hypodermis
• D. Dermis

Correct answer: C

Rationale: The hypodermis is the deepest layer of the integumentary system, located below the dermis. It serves as a layer of fat that helps insulate the body, store energy, and provide cushioning. The stratum basale is the deepest layer of the epidermis, not the entire integumentary system. The epidermis is the outermost layer of the skin, followed by the dermis, and then the hypodermis. Therefore, the correct answer is the hypodermis (choice C). Choices A, B, and D are incorrect as they do not represent the deepest layer of the integumentary system.

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