which vitamin is essential for vision and skin health

HESI A2

Anatomy HESI A2 Practice Test

1. Which vitamin is essential for vision and skin health?

A. Vitamin A
B. Vitamin C
C. Vitamin D
D. Vitamin E

Correct answer: A

Rationale: Vitamin A is the correct answer. It is crucial for maintaining healthy vision and skin. Vitamin A plays a vital role in supporting normal vision, skin health, and immune function. Specifically, it is important for the health of the retina and is essential for the formation of rhodopsin, a protein in the retina necessary for low-light and color vision. Vitamin C (Choice B) is important for collagen synthesis and immune function, but it is not primarily associated with vision health. Vitamin D (Choice C) is crucial for bone health and immune function, while Vitamin E (Choice D) acts as an antioxidant, protecting cells from damage, but neither are primarily linked to vision and skin health like Vitamin A.

2. How does the nervous system work with the muscular system?

A. The muscles of the body produce chemicals that feed the nerves.
B. The nervous system tells the muscles how to respond to the environment.
C. The nervous system releases chemicals that remove excess waste from the muscles.
D. The muscular system provides input that allows the nerves to make decisions.

Correct answer: B

Rationale: The correct answer is B because the nervous system communicates with the muscular system to control voluntary and involuntary muscle movements. The nervous system sends signals to the muscles, instructing them on how to respond to various stimuli in the environment. This communication allows for coordinated movement and responses to external and internal changes. Choice A is incorrect because muscles do not produce chemicals to feed the nerves. Choice C is incorrect because the nervous system does not release chemicals to remove waste from the muscles. Choice D is incorrect because the muscular system does not provide input for the nerves to make decisions.

3. Which of the following structures has the lowest blood pressure?

A. arteries
B. arterioles
C. venules
D. veins

Correct answer: D

Rationale: Veins have the lowest blood pressure among the listed structures. This is because veins carry blood back to the heart at a slower rate compared to arteries, arterioles, and venules. The lower blood pressure in veins allows for the efficient return of blood to the heart despite the decreased pressure. Arteries have high blood pressure as they transport blood away from the heart at a rapid rate. Arterioles are smaller branches of arteries and contribute to resistance in the circulatory system, leading to a pressure drop. Venules are small blood vessels that collect blood from capillaries and gradually converge into veins, having slightly higher pressure than veins.

4. Which hormone regulates the sleep-wake cycle?

A. Melatonin
B. Insulin
C. Cortisol
D. Thyroxine

Correct answer: A

Rationale: Melatonin, produced by the pineal gland, is the hormone that regulates the sleep-wake cycle. Its secretion is influenced by light exposure, with levels typically rising in the evening to promote sleep and falling in the morning to encourage wakefulness. Insulin is involved in regulating blood sugar levels, not the sleep-wake cycle. Cortisol plays a role in the body's stress response and circadian rhythm but is not the primary hormone regulating sleep-wake cycles. Thyroxine is a hormone produced by the thyroid gland that regulates metabolism, not the sleep-wake cycle.

5. How is pepsin utilized by the body?

A. To break down proteins
B. To break down starches
C. To emulsify fats and oils
D. To absorb water and nutrients

Correct answer: A

Rationale: Pepsin is an enzyme produced in the stomach that is essential for breaking down proteins during digestion. It functions by breaking down large protein molecules into smaller peptides, which are further broken down into amino acids for absorption in the intestines. Therefore, option A, 'To break down proteins,' is the correct answer. Choices B, C, and D are incorrect as they do not align with the specific function of pepsin in the body.