Specific Senses (5/11) Flashcards
Pathway for vision
Detect visual stimuli
convert to action potentials
send to brain
Retina
Turns certain wavelengths of light into action potentials
- contains cones (colors)
- contains rods (night vision)
Where are cones located
In the retina inside of the fovea centralis and macula
Rhodopsin
protein very sensitive to light in rods
Location of rods
many many more and cones and located further from the retina so peripheral vision is best for seeing dimly lit objects at night
Lens and cornea
cornea- first thing light passes through and protects eye
Lens- finishes job of focusing light
Iris
has a hole in center known as pupil (what actually lets light into eye) while iris acts as an umbrella to not let any excess light in
Dilator pupillae muscle
increases pupil size
Constrictor pupillae muscle
decreases muscle size
When lens changes shape…
by Ciliary body via suspensory ligament of lens
Anterior chamber (front area)
contains aqueous humor
Posterior chamber (back of the eye)
Contains vitreous humor
Beneath the retina lays a dark layer of tissue called…
Choroid - supplies blood and absorbs extra light
Outer most layer
Sclera (white color)
Cones and rods are…
synapsed to bipolar cells which then synapse to ganglia cells
Cells that are horizontal
horizontal cells are between cones/rods and bipolar cells and they inhibit photoreceptors
Amacrine cells
Between bipolar cells and ganglion cells
Visual fields
left and right
Optic Chiasm
where the fields cross and shoved to opposite side of brain
so, visuals that hit right side of left processed in right
so, visuals that hit left side of right get processed in left
outer halves of each eye stay on the same side of the brain
Optic tract
runs through the lateral geniculate nucleus (LGN) contained in the thalamus