Module 1: Intro/Anatomy Flashcards
How large is the average eyeball
24mm
How many layers of the eye
3 layers
-Tough outer layer
-consists sclera and cornea
the 1st layer of the eye
-Rich vascular tissue
-consists of iris, ciliary body, and choroid
2nd layer of the eye
-Inner layer consisting of the retina
-light is changed to electric impluses sent to the brain
the 3rd layer of the eye
What do eyelids do
procect the globe and help spread tear film
space/distance between lower and upper eyelids
palpebral aperture
hold eyelids open by contracting, closing by relaxing
Levator palpebrae superioris
-produce lipid layer and tear film
-located posterios surface of lids
Meibomian glands
tiny opening located inner aspect of the lids
Punctum
-allow tear drainage
-connect to small canals
Puncta
-3 layers giving lubrication
-keeping eyes clear and comfortable
Tear film
-1st tear film layer
-produced by meibomian glands
-prevents tear evaporation
Lipid layer
-2nd tear film layer
-secreted by lacrimal gland
Aqueous layer
-3rd tear film layer
-secreted by goblet cells
-covers the surface of cornea/conjuctiva
Mucin Layer
located superior temporal of eye
Lacrimal gland
conjunctival epithelial cells
Goblet cells
-window of the eye
- 5 layers
-avascular/fibrous/transparent
Cornea
outer most layer/ 1st layer
Epithelium
Bowman’s membrane
2nd layer
Stroma
3rd layer, thickest
Descemet’s membrane
4th layer
Endothelium
5th layer, deepest
-tough white fibrous outer coating
-supportive tissue from optic nerve
-located at the posterior of the eye to the anterior surface.
Sclera
Extraocular muscles
attach to the sclera
-Loose structure
-fibrous/elastic tissue
-located at outer part of sclera
-contains blood vessels
Episclera
-junction of cornea and sclera
-location of surgical incisions
Limbus
-mucous membrane
-covers the globe adjacent to cornea
-covers visible sclera
-lines the inside eyelids
Conjunctiva
visible sclera
Bulbar conjunctiva
inside lining of the eyelids
Palpebral conjunctiva
pocket located at bulbar and palpebral conjunctiva meet
Fornix
space directly behind cornea/infront of iris
Anterior chamber
-clear fluid that fills anterior chamber
-creates pressure within the eye
Aqueous humour
normal range is between 13-20 mmHg
Intraocular pressure (IOP)
-coloured
-circular muscle
-located behind cornea
-directly infront of lens
-regulates amount of light enters eye, by changing size.
Iris