Sensory-- only what he said would be on the test Flashcards
Eye Layers
- Outer- fibrous
- Middle=vascular= UVEAL
- inner= retinal
Outer layer of eye
fibrous =2 parts
cornea and sclera
Middle layer of eye
vascular= 3 parts
iris, ciliary body and choroid
Inner layer of eye
Retinal= 2 layers
outer retinal pigmented epithelium= RPE
Inner neural layer
Chambers of eye
3
anterior = between cornea and iris
posterior= between iris and lens
vitreous cavity= lens to retina
Conjunctiva
covers exposed part of eye and is continuous with eyelid conjunctiva
Cornea properties (# of layers, shape, function, blood supply)
- 5 layers
- transparent, convex shaped (aids in light focus on retina)
- AVASCULAR= NO REJECTION WHEN TRANSPLANTED
- Central cornea= nutrients from aqueous humor
- peripheral cornea= limbus vessel
layer of cornea`
- epithelial
- bowmans
- stroma
- Decemets membrane***
- corneal endothelium **
Cornea layers-outermost
Epithelial layer=
Non ker strat sq, microvilli
pain receptors (trigeminal n)
Can regenerate
2nd layer of cornea
Bowmans= membrane
type I collagen, no regeneration, part of stroma
3rd layer of conrea
stroma
Lattice of type I and V collagen with ECM rich in chondroitin sulfate and keratan sulfate
4th layer of cornea**
important from class
Decemet’s membrane
Thick basement membrane (type VII collagen) made by corneal endothelium
5th layer of cornea***
important from class
Endothelial layer
impermeable to prevent leakage.
produces decemets membrane
Sclera- function, characteristics
(part of outer fibrous layer of eye)
Opaque, dense CT for protection and structural support.
Insertion point for extraocular muscles
Limbus
Corneoscleral junction
next to trabecular meshwork and canal of schlemm
Aqueous humor of eye
- Production
- Flow
- clinical correlation
- made in ciliary body (posterior chamber)
- flows into anterior chamber through pupillary aperture. In anterior chamber –>trabecular network –>canal of schlemm–> aqueous veins –> episcleral veins
- obstruction of outflow= glaucoma (causes increased pressure in vitreous area= compression of stuff)
middle layer of eye
Choroid= vascular, contains melanin
Ciliary body= makes aqueous humor
Iris= 2 smooth muscle layers
Ciliary body- 2 layers
2 layers:
- Uveal =outer layer, supraciliary muscle and ciliary muscle attach to suspensory ligament. Has layer of fenestrated capillaries
- Neuroepithelial = 2 layers ciliary epithelium
- -> outer pigmented layer (cont with retinal pigm. epith)
- ->inner non pigmented layer
ciliary process- anterior portion that makes aqueous humor
Retinal pigmented epithelium is continuous with?
outer neuroepithelial layer of the ciliary body
Iris
continuation of ciliary body
Smooth muscles in uvea control the size of the pupil
2 smooth muscle layers- constrictor= PNS, dilator= SNS
Lens
associated disease
Avascular, transparent, elastic biconvex Capsule= thick basement membrane Zonula fibers change shape of lense= accommodation Cataracts- opaque lens, aging
Vitreous humor
- function
- components
DIFFERENT THAN AQUEOUS HUMOR
- fills vitreous chamber and keeps lens and retina in place
- gel-like, water and hyaluronic acid
Retinal layers–only the ones we need to know
- Pigmented epithelium
2. Neural
Functions of pigmented epithelium (X3)
- absorb light rays
- phagocytosis of old discs (from rods)
- stores and release Vit A for photoreceptors
Neural epithelium (of cornea) - components
Rods and cones
have modified cilia on outer segments
Rods
- function
- cell shape/characteristic
- Component of rods?
- for low light vision and peripheral vision
- tall cylindrical cells. Outer segments have modified cilia
- Discs (made from plasma membrane) have rhodopsin
Cones
- Main function
- cell shape/characteristics
- Components of cones
- area of retina with only cones?
- Color vision and bright light
- Shorter, also have modified cilia on outer segment
- Discs and pigments sensitive to red, green, and blue
- Fovea= only cones
Renewal of photoreceptors
comparison of rods vs cones?
Cones and rods shed disks that are phagocytosed by the pigmented epithelium. The new cones/rods are located deeper and move forward.
CONE DISCS RENEWAL IS SLOWER!
Fovea
- Location
- Contents
- type of vision
- Pit in the macula, highly represented in optic nerve and visual cortex
- 100% cones, no vessels
- MACULAR VISION important for VISUAL ACUITY