W6_01 Eye: Anatomy and Physiology Flashcards
what divides the eye into the anterior and posterior segments?
the lens
what separates the anterior and posterior chambers?
the iris
name structures in the anterior segment of the eye
sclera cornea anterior chamber iris ciliary body lens
name the perforation in the sclera to allow optic nerve penetration
lamina cribosa; meshwork that allows passage of CN II fibres
3 components of the conjunctiva
palpebral
forniceal
bulbar
describe episclera vasculature
2 layers: superficial and deep.
deep vessels are larger
name two pathologies of the episclera
episcleritis
scleritis (serious; due to rheumatoid arthritis)
what’s the division of diopter power in the eye?
cornea: 2/3 (~40D)
lens: 1/3 (~20)
3 reasons for transparency within the cornea?
avascularity
uniform structure
deturgescence
thickness of cornea?
centrally 0.54mm;
peripherally 1 mm
how many layers of the cornea?
5
what are the layers of the cornea?
epithelium Bowman's membrane stroma Descemet's (basement) membrane endothelium
difference between cornea and sclera?
collagen is coarse and irregular in sclera, causing opacity
components of the lens?
capsule
epithelium
nucleus
cortex
types of cataracts?
cortical nuclear sclerosis (aging) posterior subcapsular (steriods, diabetes)
where can intraocular lenses be implanted?
anterior chamber
posterior chamber