Eye + adnexa Flashcards
Optic nerve on bottom
Lens in middle
Cornea on top left
1: Anterior chamber
2: Posterior chamber
below 2: extraocular eye muscle
3: vitreous chamber
4: sclera
5&6: Uvea
7: Retina
Cornea
1: anterior epithelium: stratified squamous nonkeratinizing epithelium
2: Bowman membrane (anterior basement membrane)
3: Substantia propria (parallel type I collagen bundles arranged in sheets 90 degrees to each other, proteoglycan matrix)
4: Descemet membrane (posterior basement membrane)
5: Corneal endothelium: simple squamous epithelium
Lens;
lens epithelium at the top
Lens
Lens fibers on top
Capsule bottom left
Zonular fiber bottom right
Lens
with constrictor pupillae at the top
1: ciliary muscle - contracts for accommodation
2: ciliary body
Ciliary body:specialization of the uvea
Ciliary muscle bulk
Ciliary process bottom
Zonular fiber bottom right
Ciliary epithelium
Double layer of cuboidal epithelium
1: inner nonpigmented cell layer: continuous with neural retina, secrete aqueous humour
2: Outer pigmented cell layer: continuous with retinal pigment epithelium, contains melanin
3: ciliary process
Shows flow of aqueous humour
ultrafiltrate of blood produced by the ciliary body
maintains ocular pressure, nourishes lens, cornea, iris
flows from posterior chamber through pupillary aperture to anterior chamber
resorbed by trabecular channels in irido-corneal junction
blue: iris
Drainage of aqueous humour
left: trabecular network
right: irido-corneal junction
top line: Canal of Schlemm (drainage site)
Retina
top: vitreous body
1: neural retina (sensory)
2: choroid (vascular)
3: Sclera (protective/supportive)
4: nerve fascicle
5) Periorbital fat (cushion)
Retina: 0.5 mm thick, 10 distinct layers with 3 main cell types
ganglion, bipolar, photoreceptor cells
top: vitreous
1: internal limiting membrane
2: nerve fiber layer
3: ganglion cell layer
4: inner plexiform layer
5: inner nuclear layer
6: outer plexiform layer
7: outer nuclear layer
8: external limiting membrane
9: outer segments of rods and cones
10: retinal pigment epithelium
bottom: choroid
Retina
1: outer nuclear layer - contain photosensitive pigments
Cone on left, Rod on right (rods outnumber cones 15:1)
- tips of rods and cones embedded into RPE
2: RPE: phagocytose the cast off membranous discs of rods and coens
3: Bruch membrane
4: choroid
Rods: 100x more sensitive than cones
left: cilium (joins outer and inner segments)
middle: basal body
right: inner segment
bottom: membranous discs of outer segment (600-1000)
- rhodopsin in segments
Cones
- work best in bright light
- out number rods in fovea/macula
colour-specific (RGB)
bottom: membranous discs of outer segment
- contain iodopsin
top: inner segment
Retinal pigment epithelium
1: photoreceptor outer segments
Top: RPE
middle: choroid
bottom :Sclera
Left: optic disc (ganglion cell axons)
middle: macula (highest visual acuity)
right: fovea centralis (~1.5 mm in diameter, many cones)
bottom: optic nerve
Detached retina
common cause of blindness
Tips of rods/cones tear from RPE
loss of vascular supply –> degeneration of retina
Dry form of macular degeneration
gradual accumulation of plaques (drusen - lines) underneath RPE due to RPE dysfunction
Wet form of macular degeneration (less common than dry form)
more severe
abnormal growth of vessels from choroid into retina
leads to blood and clot formation
1: corneosclera
2: uvea (following are 3 parts of the uvea)
3: choroid: pigmented vascular layer under the sclera
4: ciliary body: with its muscle, epithelium and zonular fibers
5: iris: with its dilator and constrictor muscles
6: lens
7: cornea
8: sclera
9: optic nerve
yellow: anterior chamber
green: posterior chamber
both contain nutrient-rich plasma filtrate aqueous body
blue: ocular chamber - filled with vitreous body (rich in hyaluronic acid)
Iris
1: constrictor pupillae: parasympathetic
2: anterior surface - no epithelial layer; consists of a stroma filled with fibroblasts and melanocytes
3: dilator pupillae: sympathetic; radially-arranegd thin layer of myoepithelial cells
4: double cuboidal pigmented epithelium (posterior) - continuous with epithelium coverage of ciliary body
Lens
Lens capsule outer layer
inner to it, lens epithelium: simple cuboidal epithelium. Found only on the anterior surface
1: lens fibers: elongated columnar epithelial cells lacking nuclei, rich in crystalline protein
1: ciliary body
2: ciliary epithelium
3: retina: extends from ora serrata to the optic disc
4: ora serrata: transition point from the ciliary epithelium to the neural retina, beginning of the choroid layer of the uvea
5: choroid
Eyelid
Left: inner palpebral conjunctivae: composed of stratified columnar epithelium with goblet cells
Right: thin skin
Eyelid (inner surface)
top: tarsal plate: tough internal plate of fibrous tissue
middle: palpebral conjunctivae: stratified columnar epithelium with goblet cells
bottom: Meibomian gland: modified sebaceous gland
Left: smooth muscle (tarsal muscle of Muller)
Right: skeletal muscle (orbicularis oculi)
Lacrimal gland: tubulo-acinar serous gland
Top: excretory ducts
Left: stroma
Right: parenchyma
Star: lymphocytes, antibody-producing plasma cells
