The Eye Flashcards
what is the function of the retinal pigmented epithelium
contains melanin to ensure theres not excessive light refraction
anchors the photoreceptor cells in the neural layer
what are the 3 types of photoreceptor cells in the neural layer of the retina
rods
cones
horizontal cells
what do rods do
responsible for black and white vision
what do cones do
responsible for coloured vision and high definition
what do horizontal cells do
responsible for lateral inhibition
what are the layers of the retina
Pigmented layer and Neural layer
what region of the retina contains no photoreceptor cells
the blind spot where the optic nerve leaves
what is the macula responsible for
central vision and acuity
what type of photoreceptor is abundant in the macula
cones
what artery supplies the retina
central retinal artery
what will happen to the optic disc in raised inter cranial pressure
it will swell
describe the light reflex
light stimulates the afferent CN II
nerve synapses with both Edinger Westphal Nuclei
efferent CN III gives a parasympathetic response causing direct and consensual pupil contraction via constrictor papillae
in what area are the edinger westphal nuclei found
pretectal area
describe the accommodation reflex
light stimulates the afferent CN II
nerve synapses at the lateral geniculate nucleus and goes to the primary visual cortex in the occipital lobe
efferent CN III causes convergence of pupils, pupil constriction and ciliary muscle contraction to give a more convex lens
describe the root of the optic tracts
they go to the lateral geniculate nucleus in the thalamus where they then spilt into radiations
