anatomy of the eye and orbit Flashcards
3 coats of the eye
fibrous
vascular
sensory
what is the fibrous coat made from
and what structures are included in it
collagen
sclera and cornea
whats included in vascular coat x3
iris
ciliary body
choriod
whats included in sensory coat
retina
whats the ora serrata
serrated edge of retina
type of collagen in parts of fibrous coat
sclera- irregular and thick
cornea- uniform and fine
what part of the eyeball do muscles attatch to
sclera
what suspends the lens
and produces AH
ciliary body
what does the choriod do
Supplies blood to outer layers of retina
ant vs post segment position and liquid type
anterior segment- infront of lens and contains Aqueous Humor(AH) which is WATERY
posterior segment- behind lens and contains Vitreous Humor(VH) which is a GEL
what attaches lense to ciliary body
zonules
purpose of AH and VH
AH- maintains intraocular pressure
VH- cushions retina
further chambers in anterior segment
where they sit
Anterior chamber (AC) in front of iris
Posterior chamber (PC) behind iris but in front of the lens
route of AH:
what helps with drainage
where is it absorbed, what angle
where is it absorbed to
trabecular meshwork
in canal of schlem at angle of anterior chamber
veins
what gland is found in eyelid
and what is it encapsulated by
meibomian gland
in tarsal plate
what is the conjuctiva
thin vascular membrane that covers inner surface of eyelids and loops back over sclera
DOES NOT COVER CORNEA
nerve supply to lacrimal gland
parasympathetic from facial nerve
tear drainage
through punctae on the medial side of each eyelid
into lacrimal sac
Then through nasolacrimal duct
into inferior meatus of nose
imotor innervation: ntrinsic vs extrinsic muscles
Intrinsic muscles – control pupil diameter & lens curvature
Extrinsic muscles - move
the eye.
motor innervation: 3 intrinsic muscles
what they do
nerve supply
oculomotor:
1. Ciliaris muscle - lens
2. Constrictor pupillae
Sympathetic:
3. Dilator pupillae
motor innervation: were do the recti muscles arise fom
annular fibrous ring
see presentation for muscle diagram
motor innervation: what muscle opens/closes eyelids
opens- LPS
closes- obicularis oculi
motor innervation: 3 nerves that supply extrinsic muscles
what do they supply
oculomotor III- (3 things to remember)
all recti (except lateral)
inf oblique
LPS
trochlear IV- superior oblique
abducent VI- lateral rectus
motor innervation: what nerve supplies superior oblique
trochlear VI
motor innervation: what nerve supplies lateral rectus
abducens VI
motor innervation: what nerve supplies all eye muscles except SO and LR
occulomotor III
motor innervation: what nerve supplies LPS
oculomotor III
where do the cranial nerves supplying eye leave skull
optic- optic foramen
oculomotor, abducens, trochlear- sup orbital fissure
sensory innervation: what nerve supplies general sensory
and fissures it goes through
trigeminal 2 branches:
V1 ophthalmic- upper eyelid and eye ball- sup orbital fissure
V2 maxillary- inf orbital fissure
what main artery supplies eye
what is it a branch of
what foramen does it enter through
ophthalmic
ICA
optic foramen- alongside optic nerve
what branch of ophthalmic artery supplies inner retina
how does it travel
central retinal artery
within optic nerve
what branches of ophthalmic supply the posterior choroid and outer retina
Short posterior ciliary arteries
what branch of opthalmic artery supplies the
anterior choroid, ciliary body and iris
Long posterior ciliary arteries
what veins drain the cavernous sinus
sup and inf ophthalmic veins
what does the eye develop from
neural tube
where do optic vesicles grow from
from diencephalic part of neural tube towards
surface ectoderm.
steps in formation of optic vesicle x4
optic vesicles
lens placode
optic cup
2 layered optic cup
what does ectoderm form in eye
eyelids, conjunctiva, corneal epithelium
first layer so outermost
what does mesenchyme form in eye
choroid, stroma of cornea, sclera and
extraocular muscles.
main middle stuff
what does lens fibres form from
epithelium of lens vesicle & later loose
their nucleii.
