Eye 2

Question 1

10 Layers of Retina (Inner to Outer)

Answer 1

Inner limiting membrane (Muller cell)
Nerve fibers layer (axons of retinal ganglion)
Ganglion cell layer (retinal ganglion cells)
Inner plexiform layer (amacrine, bipolar cell processes)
Inner nuclear layer (amacrine, bipolar, horizontal cells)
Outer plexiform layer (horizontal, photoreceptor)
Outer nuclear layer (photoreceptor cell bodies)
Outer limiting membrane
Inner and outer segments of rods and cones
Pigmented epithelium (tight junctions)

Question 2

Functions of retinal pigment epithelium

Answer 2

• light absorption
• epithelial transport (glucose, vitamin A)
• glia (buffer potassium)
• visual cycle (restore retinal)
• phagocytosis (shedded outer segment of rods)
• secretion (growth factors)
• synthesis of melanin and Bruch’s membrane

Question 3

Rods

Answer 3

• photopigment = rhodopsin (bleach = opsin + retinol)
• outer segment = disk synthesis (SHED)
• inner segment
• spherule (synaptic contacts w/ bipolar + horizontal)

Question 4

Cones

Answer 4

• photopigment = iodopsin (colour – blue, green, red)
• outer segment = continuous disks (NO SHED)
• inner segment
• pedicle (large synaptic contacts) – synaptic ribbon

Question 5

Inner Nuclear, Inner Plexiform, Ganglion Cell Layer

Answer 5

Ganglion (multiple bipolar cells –> optic nerve)
Bipolar (single ganglion cell – info from cones + rods)
Amacrine (neurites release NT + receive synaptic)

Question 6

Fovea

Answer 6

• highest visual acuity
• photoreceptor:bipolar:ganglion (1:1:1)
• cones only (light directly hits photoreceptors)

Question 7

Macula

Answer 7

• inner retina layers = yellow pigment
• absorbs short (blue) wavelength light

Question 8

Optic Disk

Answer 8

• site where axons of ganglion cells turn into optic nerve
• no photoreceptor cells
• thick nerve fiber layer