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. What is the primary function of the skin?

A. To regulate body temperature
B. To protect the body from external damage
C. To produce vitamin D
D. To produce red blood cells

Correct answer: B

Rationale: The primary function of the skin is to protect the body from external damage. While the skin also helps regulate body temperature and produces vitamin D in response to sunlight, its main role is to act as a barrier against harmful external factors, such as pathogens and physical injuries. Choices A, C, and D are incorrect because although the skin does play a role in regulating body temperature and producing vitamin D, its primary function is providing protection against external threats.

3. Which part of the nervous system includes the femoral, radial, and ulnar nerves?

A. Somatic
B. Autonomic
C. Sympathetic
D. Parasympathetic

Correct answer: A

Rationale: The correct answer is A: Somatic. The femoral, radial, and ulnar nerves are all part of the somatic nervous system, responsible for controlling voluntary movements and sensory input. These nerves innervate muscles and skin throughout the body, allowing conscious control of movements and sensations. The somatic nervous system is distinct from the autonomic nervous system, which regulates involuntary bodily functions. Choices B, C, and D are incorrect because the autonomic nervous system (B) is responsible for involuntary functions, while the sympathetic (C) and parasympathetic (D) divisions are subdivisions of the autonomic nervous system, not the somatic nervous system.

4. Which mineral helps maintain fluid balance in the body?

A. Potassium
B. Cobalt
C. Chromium
D. Sulfur

Correct answer: A

Rationale: Potassium is the mineral that helps maintain fluid balance in the body. It plays a crucial role in regulating the amount of fluid inside and outside the body's cells, thereby helping to maintain proper hydration levels. Potassium works in conjunction with sodium to regulate fluid balance and is essential for proper muscle function, nerve transmission, and heart health. Cobalt, chromium, and sulfur do not play significant roles in maintaining fluid balance in the body, making them incorrect choices for this question.

5. What is the role of the mitochondria in the cell?

A. Protein synthesis
B. Energy production
C. Breaking down waste
D. Cell division

Correct answer: B

Rationale: The correct answer is B: Energy production. Mitochondria are known as the powerhouses of the cell because they generate adenosine triphosphate (ATP) through the process of cellular respiration. ATP is a molecule that stores and releases energy, providing the cell with the necessary energy for various activities and functions. Choices A, C, and D are incorrect. Protein synthesis primarily occurs in the ribosomes, breaking down waste is mainly carried out by lysosomes, and cell division is orchestrated by the nucleus and other organelles like the centrioles.