Which sequence lists the early steps from photoreceptors to the optic nerve?

Which sequence lists the early steps from photoreceptors to the optic nerve?

• A. Photoreceptor → bipolar cell → ganglion cell → optic nerve.
• B. Photoreceptor → optic nerve → bipolar cell → ganglion cell.
• C. Bipolar cell → photoreceptor → ganglion cell → optic nerve.
• D. Ganglion cell → bipolar cell → photoreceptor → optic nerve.

Answer: (A)

Signals flow through retinal circuitry from photoreceptors to the brain. Photoreceptors detect light and convert it into electrical signals, these signals are then passed to bipolar cells, which relay them to ganglion cells. The axons of the ganglion cells bundle together to form the optic nerve, carrying the information onward. Therefore, the early steps from photoreceptors to the optic nerve follow this sequence: photoreceptor → bipolar cell → ganglion cell → optic nerve. This ordering fits because the optic nerve is made up of ganglion cell axons and comes after the retinal neurons in the circuit; other sequences would place components in the wrong order or skip the retinal processing stage.

Signals flow through retinal circuitry from photoreceptors to the brain. Photoreceptors detect light and convert it into electrical signals, these signals are then passed to bipolar cells, which relay them to ganglion cells. The axons of the ganglion cells bundle together to form the optic nerve, carrying the information onward. Therefore, the early steps from photoreceptors to the optic nerve follow this sequence: photoreceptor → bipolar cell → ganglion cell → optic nerve. This ordering fits because the optic nerve is made up of ganglion cell axons and comes after the retinal neurons in the circuit; other sequences would place components in the wrong order or skip the retinal processing stage.