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 type of joint allows for the greatest range of motion?

• A. Hinge joint
• B. Ball-and-socket joint
• C. Pivot joint
• D. Saddle joint

Correct answer: B

Rationale: The correct answer is B: Ball-and-socket joint. The ball-and-socket joint, like the shoulder joint, allows for the greatest range of motion due to its structure, enabling movement in multiple directions. In contrast, hinge joints, pivot joints, and saddle joints have more restricted ranges of motion compared to ball-and-socket joints. Hinge joints primarily allow movement in one plane, pivot joints allow rotation around a central axis, and saddle joints have limited movement compared to ball-and-socket joints.

3. Which type of waves require a medium (solid, liquid, or gas) to propagate?

• A. Transverse waves
• B. Longitudinal waves
• C. Electromagnetic waves
• D. Surface waves

Correct answer: B

Rationale: Longitudinal waves require a medium (solid, liquid, or gas) to propagate because the particles in the medium move parallel to the direction of the wave. As a result, they rely on the medium for transmission. Transverse waves, on the contrary, do not need a medium and can travel through a vacuum, making choice A incorrect. Electromagnetic waves, represented by choice C, do not require a medium as they consist of oscillating electric and magnetic fields that can propagate through a vacuum. Surface waves, the option in D, involve a combination of both longitudinal and transverse motion and do require a medium to travel, but longitudinal waves are the ones that strictly depend on a medium for propagation.

4. Which blood vessels carry oxygenated blood from the heart to the rest of the body?

• A. Pulmonary arteries
• B. Pulmonary veins
• C. Systemic arteries
• D. Systemic veins

Correct answer: C

Rationale: The correct answer is systemic arteries. Systemic arteries carry oxygenated blood from the heart to the rest of the body to provide oxygen and nutrients to tissues. Pulmonary arteries carry deoxygenated blood from the heart to the lungs for oxygenation. Pulmonary veins transport oxygenated blood from the lungs back to the heart. Systemic veins return deoxygenated blood from the body tissues to the heart for reoxygenation. Therefore, choices A, B, and D are incorrect as they do not carry oxygenated blood away from the heart to the body.

5. Myelin sheath is a fatty substance that insulates and protects the long extensions of some nerve cells. It is produced by:

• A. Schwann cells
• B. Astrocytes
• C. Neurons
• D. Oligodendrocytes

Correct answer: A

Rationale: Schwann cells are indeed responsible for producing the myelin sheath in the peripheral nervous system. These cells wrap around axons to form the myelin sheath, which enhances the speed of nerve impulse conduction. In the central nervous system, oligodendrocytes are responsible for producing the myelin sheath. Astrocytes provide support and maintenance functions for neurons, while neurons are the nerve cells themselves and do not produce myelin. Therefore, the correct answer is Schwann cells as they are specifically involved in myelin production in the peripheral nervous system.

Similar Questions