Nursing Elites

1. 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.

2. Which of the following hormones is primarily responsible for regulating metabolism?

• A. Insulin
• B. Testosterone
• C. Adrenaline
• D. Thyroid hormone

Correct answer: D

Rationale: Thyroid hormone is the correct answer as it is primarily responsible for regulating metabolism. It plays a crucial role in controlling the body's metabolic rate, affecting how the body uses energy from food. Thyroid hormone levels can influence metabolism, energy production, and body weight regulation. Insulin, choice A, is involved in regulating blood sugar levels, not directly metabolism. Testosterone, choice B, is a sex hormone that primarily affects the development of male reproductive tissues. Adrenaline, choice C, is involved in the fight-or-flight response and not primarily responsible for regulating metabolism.

3. What type of muscle is found in the walls of hollow organs like the intestines?

• A. Cardiac muscle
• B. Smooth muscle
• C. Skeletal muscle
• D. Voluntary muscle

Correct answer: B

Rationale: Smooth muscle is the correct type of muscle found in the walls of hollow organs like the intestines. It is responsible for movements such as peristalsis, aiding in the movement of food and other materials through the digestive system. Cardiac muscle (Choice A) is found in the heart and is responsible for the heart's contractions, not in hollow organs like the intestines. Skeletal muscle (Choice C) is attached to bones and responsible for voluntary movements, not in hollow organ walls. Voluntary muscle (Choice D) is another term for skeletal muscle, which is under conscious control, unlike smooth muscle in hollow organ walls.

4. 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.

5. Which of the following is not a component of blood?

• A. Red blood cells
• B. White blood cells
• C. Platelets
• D. Cartilage

Correct answer: D

Rationale: The correct answer is D: Cartilage. Cartilage is not a component of blood. Blood primarily consists of red blood cells, white blood cells, and platelets. Red blood cells are responsible for carrying oxygen, white blood cells are part of the immune system, and platelets are essential for blood clotting. Cartilage, on the other hand, is a type of connective tissue found in various parts of the body, such as the joints and nose, but it is not present in the blood. Therefore, choices A, B, and C are incorrect as they are components of blood, while choice D, Cartilage, is the correct answer as it is not a component of blood.

Similar Questions