(40) The Visual System Flashcards
What part of the brain in responsible for visual perception?
occipital cortex
What part of the brain in responsible for visual memory?
parietal an temporal
What part of the brain in responsible for visual reflexes?
brainstem and spinal cord
What part of the brain in responsible for circadian rhythm
pineal gland and dienchephalon
what focuses the incoming light from objects we see to create a crisp image
fovea
What happens to the light from an object after it enters our eye to get to the retina?
refracted by cornea inverted through pupil refracted by lens projected onto fovea fovea focuses/fine tunes light light hits retina
how is the image of the object we are seeing oriented on the fovea in our eye?
inverted and smaller
*due to refraction by cornea and lens
What muscle controls lens refraction and how it is innervated
cilliary muscle via sympathetic and parasympathetic control
protective later to the retinal and choroid
sclers
choroid provides blood flow and nutrients to….
photoreceptors and RPE cells = OUTER retina
describe the circulation in the fovea
there is NONE = no blood vessels bc blood distorts the image
describe the cellular organization of the retina
photoreceptor cell bodies lie in outer nuclear layer and project to outer flexiform layer where they synapse with bipolar cells who’s cell bodies are found in the inner nuclear layer. these bipolar cells project to ganglion cells in the ganglion layer. the ganglion cell projections coalesce to form the optic N
provides the barrier between the retina and the choroid
retinal pigmented cells
support the photoreceptor by providing nutrients
RPE
What are the interneurons that lie in the retina and what cells do they synapse with and what is their function?
horizontal (outer plexiform layer) –modulate photoreceptors and bipolar cells
amacrines (inner plexiform layer) –modulate bipolar cells
what form the blind spot?
optic N entry into retina
how are the retinal cells arranged in the fovea?
radially to minimizes distortion of the image