which vitamin is important for vision

HESI A2

HESI A2 Practice Test Anatomy and Physiology

1. Which vitamin is important for vision?

A. Vitamin A
B. Vitamin C
C. Vitamin D
D. Vitamin K

Correct answer: A

Rationale: The correct answer is Vitamin A. Vitamin A is crucial for maintaining healthy vision, particularly in low-light conditions. It plays a key role in the health of the retina and is necessary for the proper functioning of the eye. Deficiency in Vitamin A can lead to night blindness and other vision problems. Vitamin C is important for the immune system and skin health, not specifically for vision. Vitamin D is essential for bone health and overall well-being, but it is not directly related to vision. Vitamin K is important for blood clotting, but it is not specifically linked to vision.

2. Which of the following is not part of the central nervous system?

A. Retina
B. Spinal cord
C. Brain
D. Heart

Correct answer: B

Rationale: The central nervous system consists of the brain and spinal cord, which are responsible for processing and coordinating information. The retina is part of the eye, while the heart is part of the circulatory system. Therefore, the correct answer is 'Spinal cord' as it is not part of the central nervous system.

3. Which is a secondary defense for the body against pathogens?

A. Tears
B. Urine
C. Inflammation
D. Mucus

Correct answer: C

Rationale: Inflammation is a secondary defense mechanism for the body against pathogens. When tissues are injured or infected, inflammation occurs as a protective response involving increased blood flow, white blood cell migration, and tissue repair. This process helps contain and eliminate pathogens, preventing them from spreading further in the body. Tears (Choice A) are a primary defense containing lysozyme and other antimicrobial agents. Urine (Choice B) is typically considered a non-specific defense mechanism due to its flushing action in the urinary tract. Mucus (Choice D) acts as a physical barrier and traps pathogens, also considered a primary defense mechanism.

4. What is the primary function of the skin in the integumentary system?

A. Regulating body temperature
B. Protecting the body from external damage
C. Producing red blood cells
D. Producing hormones

Correct answer: B

Rationale: The primary function of the skin in the integumentary system is to protect the body from external damage. The skin acts as a barrier against pathogens, UV radiation, and physical trauma. While the skin does help regulate body temperature by sweating and vasodilation, its main role is protection. Skin does not produce red blood cells; this is the function of the bone marrow. Hormones are primarily produced by endocrine glands, not the skin.

5. What is the function of the gallbladder in the digestive system?

A. To produce bile
B. To store and concentrate bile
C. To detoxify harmful substances
D. To regulate blood sugar

Correct answer: B

Rationale: The gallbladder's main function is to store and concentrate bile produced by the liver. Bile is essential for the digestion and absorption of fats in the small intestine. Therefore, the correct answer is B, as the gallbladder acts as a reservoir for bile rather than producing it. Choices A, C, and D are incorrect because the gallbladder does not produce bile, detoxify harmful substances, or regulate blood sugar in the digestive system.