Visual System Flashcards
the blood supply of the photoreceptors of the eye is the _____ , and the supply of the retina and distal CN II is the ______.
choroid (fed by ciliary arteries), central artery of retina…both stem from the opthalmic artery which is a branch of the internal carotid artery.
detached retina occurs between ____ and ______ which take their blood supply from the _____
pigment epithelium, photoreceptive layer, choroid
In rods, the photopigment is ______ and transduction depolarizes rod which _______ ________ __________
rhodopsin, decreases glutamate release
The action of Rhodopsin is to interact with _______ and ______ to convert ______ to _______
transducin, phosphodiesterase, cGMP, 5’GMP
L-cone and M-cone are on ____ (chromosome) but S-cone is on ______ (chromosome)
X-chromosome, autosome
horizontal cells found in the _____ layer have this action (1). Amacrine cells found in ______ layer have this action (2)
outer plexiform layer, (1) sharpen edges of images, inner plexiform layer, (2) increase ganglion sensitivity to moving stimuli
open channels are for ________ and closed channels are for ________. If glutamate binds an open channel, this happens:
off center bipolar and ganglion cells, on center bipolar and ganglion cells cations are allowed through the channel, hyperpolarizing each cell type
neural tube forms the ______ and the neural crest forms the ______
CNS, PNS (cells with nuclei outside brain and spinal cord)
The neural tube is _______ but is found in the ________. It invaginates and makes contact with _______ which induces formation of _________.
ectoderm, mesoderm, surface ectoderm, lens placodes
inner layer of invaginated optic vessicle is _______ and the outer layer is the ________. The layer lying outside of the invagination is the _______.
pigment epithelium, retina, lens placode
lens and cornea are avascular in adult and get nutrients from _________
aqueous humor
neural crest-derived structures include:
sclera, stroma of cornea, ciliary body, iris, choroid
PAX 6 is master gene for eye development and regulates differentiation of _____ and ______. PAX2 regulates differentiation of ______ and ________
optic cup, lens optic stalk, optic nerve
__________ may occur if choroid fissure fails to close in 7th week of development. _________ is the most common phenotype. Mutations in ______ have been linked to optic nerve phenotypes.
Coloboma (cleft), Coloboma iridis (cleft iris), PAX2
cytoskeleton holding each photoreceptor to the basal body is made of:
9 pairs of microtubules
The 3 functions of the pigment epithelium are:
- supplies neural retina with glucose and ions 2. protects photoreceptors from damaging light 3. periodically phagocytoses part of photoreceptor
________ form the optic nerve which exits at the optic disk
ganglion cell axons
cataracts can be caused by these 5 things:
congenital (ex. rubella infection), diabetes, medications, UV, aging
ciliary muscle ______ in response to near objects which _______ the lens.
contracts, fattens
Mydriasis is caused by _________ muscle, miosis is caused by the _______ muscle.
pupillary sphincter, pupillary dilator
glaucoma is caused by:
blockage of canal of Schlemm
cornea layers from outer to inner:
non-keratinized squamous epithelium, Bowman’s membrane (basal lamina), Descemet’s membrane (basement membrane), endothelial cells
The 4 types of retinal ganglion cells are:
parasol (magnocellular), midget (parvocellular), small bistratified, intrinsically photoreceptive (ipRGC)
________ cells receive input primarily from rod cells and have large receptive fields. _______ cells receive input primarily from cone cells and have small receptive fields.
Parasol (M), Midget (P, Beta)
