Which statement about the outer nuclear layer is true?

Which statement about the outer nuclear layer is true?

• A. It contains neurons from the optic nerve
• B. It nourishes the inner retina
• C. It contains the cell nuclei of photoreceptors
• D. It is located behind Bruch's membrane

Answer: (A)

The outer nuclear layer houses the cell bodies (nuclei) of the photoreceptors—the rods and cones. This layer sits just inside the photoreceptor layer, and you can think of it as the region where the photoreceptors’ nuclei are packed before their processes extend toward the outer plexiform layer and the retinal pigment epithelium. The neurons that form the optic nerve are retinal ganglion cells, whose cell bodies are in the ganglion cell layer, and their axons bundle together to become the optic nerve—so they are not in the outer nuclear layer. Nourishment of the inner retina comes from the retinal vasculature and surrounding choroidal circulation, not from the outer nuclear layer itself. Bruch’s membrane lies behind the retina (between the RPE and the choroid), so the outer nuclear layer is not located behind Bruch’s membrane.

The outer nuclear layer houses the cell bodies (nuclei) of the photoreceptors—the rods and cones. This layer sits just inside the photoreceptor layer, and you can think of it as the region where the photoreceptors’ nuclei are packed before their processes extend toward the outer plexiform layer and the retinal pigment epithelium. The neurons that form the optic nerve are retinal ganglion cells, whose cell bodies are in the ganglion cell layer, and their axons bundle together to become the optic nerve—so they are not in the outer nuclear layer. Nourishment of the inner retina comes from the retinal vasculature and surrounding choroidal circulation, not from the outer nuclear layer itself. Bruch’s membrane lies behind the retina (between the RPE and the choroid), so the outer nuclear layer is not located behind Bruch’s membrane.