which structure in the brain regulates sleep and wakefulness

HESI A2

HESI A2 Anatomy and Physiology Quizlet

1. Which structure in the brain regulates sleep and wakefulness?

A. Hypothalamus
B. Thalamus
C. Pineal gland
D. Cerebellum

Correct answer: C

Rationale: The pineal gland, located in the brain, is responsible for regulating sleep and wakefulness by secreting the hormone melatonin. Melatonin plays a crucial role in controlling the sleep-wake cycle, with higher levels at night inducing sleepiness. The hypothalamus (Choice A) regulates various physiological processes but is not primarily responsible for sleep-wake cycles. The thalamus (Choice B) is involved in relaying sensory information but not specifically in regulating sleep. The cerebellum (Choice D) plays a role in coordination and motor control rather than sleep regulation.

2. What is the function of the coronary artery?

A. It carries oxygenated blood to the heart muscle.
B. It carries deoxygenated blood to the lungs.
C. It distributes blood to the body.
D. It supplies blood to the heart muscle.

Correct answer: D

Rationale: The correct answer is D: 'It supplies blood to the heart muscle.' The coronary artery's main function is to supply oxygenated blood to the heart muscle, ensuring that the heart receives the necessary nutrients and oxygen it needs to function properly. Choices A, B, and C are incorrect because the coronary artery specifically delivers oxygenated blood to the heart muscle, not deoxygenated blood to the lungs or blood to the rest of the body.

3. The shoulder is _________ to the elbow.

A. posterior
B. proximal
C. distal
D. medial

Correct answer: B

Rationale: Proximal refers to a position closer to the point of attachment or origin. In this case, the shoulder is closer to the point of attachment to the body compared to the elbow, making it proximal to the elbow. 'Posterior' refers to the back side of the body, 'distal' means farther away from the point of attachment, and 'medial' refers to the middle of the body. These terms do not accurately describe the relationship between the shoulder and the elbow in this context.

4. Where are B-lymphocytes produced?

A. Thymus
B. Red bone marrow
C. Lymph nodes
D. Spleen

Correct answer: B

Rationale: B-lymphocytes are produced in the red bone marrow. The red bone marrow is the primary site for B-cell development, where they mature before entering the circulation. The thymus is responsible for T-lymphocyte maturation, not B-lymphocytes. Lymph nodes and spleen play roles in immune responses but are not the primary sites for B-lymphocyte production.

5. Which type of muscle tissue is voluntary?

A. Cardiac muscle
B. Skeletal muscle
C. Smooth muscle
D. Striated muscle

Correct answer: B

Rationale: The correct answer is B, Skeletal muscle. Skeletal muscle is a type of voluntary muscle tissue, allowing conscious control over its movement. Unlike smooth and cardiac muscle, which are involuntary, skeletal muscle is under direct voluntary control. Cardiac muscle (choice A) is involuntary and found in the heart. Smooth muscle (choice C) is also involuntary and found in the walls of internal organs. While skeletal muscle is striated (contains stripes), choice D is not the best answer as it does not specifically address the voluntary nature of skeletal muscle.