XVII - Organs of Special Senses Flashcards
First and most powerful structure of the optical system
cornea
Center of vision
fovea
Enable the lens to change its shape
zonula
Middle vascular layer of the eye
uvea
film of the eye
retina
Area of the eye without sensory cells
optic disk
First part of the brain to receive visual input
optic chiasm
Relay station of the visual cortex
lateral geniculate body
Keeps images focused on the retina
lens
Layer of blood vessel that supplies blood to the retina
choroid
Produces aqueous humor
ciliary body
Blocked in glaucoma
canal of Schlemm
Lens: highly elastic basement membrane covered by a single layer of cuboidal cells, thickest near the equator, thinnest posteriorly
capsule
Lens: forms the bulk of the lens, composed of long thin tightly packed cells who lost their nuclei and form fibers
cortex/fiber
Cornea: stratified non-keratinizing squamous, 5-6 layers, exposed to air, one of the richest sensory nerve supplies of any eye tissue
epithelium
Cornea: composed of collagen fibers, acellular, contributes greatly to the stability and strength of the cornea
Bowman’s membrane
Cornea: thickest layer, collagen type III and IV, avascular
stroma
Cornea: basement membrane
Descemet’s membrane
Cornea: simple squamous, exposed to aqueous humor, responsible for metabolic exchanges
endothelium
Retina: not photosensitive
anterior
Retina: photosensitive, optical part
posterior
Retina: contains photosensitive cells (rods & cones)
outer layer
Retina: contains bipolar neurons
intermediate layer
Retina: contains ganglion cells
internal layer
Retina: where the retina converges to form the optic nerve
optic disk (optic nerve head, papilla of the optic nerve
Retina: blind spot
optic disk
Retina: oval-shaped highly pigmented yellow spot near the center of the retina
macula
Retina: area of highest visual acuity
fovea
Retina: small pit in the center of the macula, contains the highest concentration of cone cells
fovea
Retina: separates the retina from the vitreous humor
inner limiting membrane
Retina: unmyelinated axons of ganglion cells
optic nerve fibers
Retina: site of action potential generation, receptor cells
ganglion cells
Retina: synapses between bipolar cells of dendrites of ganglion cells, closer to vitreous
inner plexiform
Retina: nuclei of bipolar, amacrine, horizontal and müller cells
inner nuclear
Retina: synapses between bipolar cells of dendrites of ganglion cells, farther from vitreous
outer plexiform
Retina: nuclei of rods and cones
outer nuclear
Retina: separates outer nuclear and photoreceptor layers
outer limiting membrane
Retina: contain Na channels
photoreceptors