Anatomy and Physiology II Practice Test

A deficiency in vitamin A can lead to night blindness because this vitamin plays a crucial role in the production of rhodopsin, a protein in the retina that is essential for low-light and nighttime vision. Vitamin A is critical for the maintenance of normal vision, and it helps the eyes adapt to darkness. When there is an insufficient amount of vitamin A in the body, the eyes struggle to adjust to dim lighting, resulting in difficulties seeing at night or in low-light conditions.

Other vitamins listed do not directly affect night vision. For instance, vitamin K is mainly involved in blood clotting, while vitamin E has antioxidant properties that protect cell membranes but has no direct link to vision. Vitamin C is important for overall health and immune function, but it does not have a specific role in night vision. Thus, the link between vitamin A deficiency and night blindness is well-established in the study of anatomy and physiology.