Question

There are three layers of neurons in the retina.
Тhe axons of which of these neuron layers form the optic nerves?

a. rod cells

b. bipolar cells

c. cone cells

d. ganglion cells

Answer 1

Answer:

d. ganglion cells

Explanation:

There are 10 ten layers of retina from outermost to innermost:

1. Layer of retinal pigment epithelium ( this is the outermost layer of retina)
2. Layers of rods and cones (this is the layer of photoreceptors i.e. the cells that are responsible for vision)
3. External Limiting membrane (also known as Outer limiting membrane, it is a network like structure))
4. Outer Nuclear Layer (this layer contains the nuclei of rods and cones i.e. photoreceptors)
5. Outer plexiform Layer (this layer contains synapses of rods and cones i.e. photoreceptors with dendrites of bipolar cells)
6. Inner Nuclear Layer (this layer contains nuclei of bipolar cells)
7. Inner plexiform Layer (this layer contains synapses of bipolar cells with dendrites of ganglion cells)
8. Ganglion cell layer (this layer contains nuclei of ganglion cells)
9. Nerve fiber layer (this layer contains axons of ganglion cells, it is these axons that form the optic nerve)
10. Internal limiting membrane (this layer lies next to the vitreous body which is a jelly-like, transparent substance that fills the space between the retina and the lens)

QUESTION:

a. rod cells

This is the incorrect answer choice as the axons of rods synapse with dendrites of bipolar cells in outer plexiform layer.

b. bipolar cells

This is the incorrect answer choice as the axons of bipolar cells synapse with dendrites of ganglion cells in inner plexiform layer.

c. cone cells

This is the incorrect answer choice as the axons of cones synapse with dendrites of bipolar cells in outer plexiform layer.

d. ganglion cells

This is the correct answer choice as axons of ganglion cells form the fibers of optic nerve (Cranial Nerve II/ CNII).