Which structure converts light into nerve impulses that are carried to the brain?

Which structure converts light into nerve impulses that are carried to the brain?

• A. Pupil
• B. Retina
• C. Optic nerve
• D. Iris

Answer: (B)

Phototransduction in the retina is what’s being tested: light is detected by photoreceptors in the retina (rods and cones), which convert light energy into electrical signals that can be transmitted as nerve impulses toward the brain. This conversion happens right in the retinal tissue, starting the visual pathway. The signals then travel via the optic nerve to the brain for processing. The iris and pupil regulate how much light enters, not the signaling itself, and the optic nerve carries impulses rather than converting light.

Phototransduction in the retina is what’s being tested: light is detected by photoreceptors in the retina (rods and cones), which convert light energy into electrical signals that can be transmitted as nerve impulses toward the brain. This conversion happens right in the retinal tissue, starting the visual pathway. The signals then travel via the optic nerve to the brain for processing. The iris and pupil regulate how much light enters, not the signaling itself, and the optic nerve carries impulses rather than converting light.