Which structure in the visual pathway is located first?

Which structure in the visual pathway is located first?

• A. Optic nerve
• B. Optic chiasm
• C. Visual cortex
• D. Retina

Answer: (D)

Light detection and initiation of the neural signal happen in the retina. It houses the photoreceptors (rods and cones) that transduce light into electrical signals, which then travel through bipolar and ganglion cells. The axons of these ganglion cells bundle together to form the optic nerve and carry the information toward the brain. The other structures—optic nerve is next after the retina, the optic chiasm is a subsequent relay where some fibers cross, and the visual cortex is reached only after processing through the lateral geniculate nucleus and optic radiations. So the retina is the starting point of the visual pathway.

Light detection and initiation of the neural signal happen in the retina. It houses the photoreceptors (rods and cones) that transduce light into electrical signals, which then travel through bipolar and ganglion cells. The axons of these ganglion cells bundle together to form the optic nerve and carry the information toward the brain. The other structures—optic nerve is next after the retina, the optic chiasm is a subsequent relay where some fibers cross, and the visual cortex is reached only after processing through the lateral geniculate nucleus and optic radiations. So the retina is the starting point of the visual pathway.