Anatomy/Physiology

Question 1

External/surface

Answer 1

eyelids, caruncle
conjunctiva, limbus
lacrimal glands, canaliculi, sac,, puncta, papillae, NLD

Question 2

Three Layers

Answer 2

outer fibrous:

• cornea
• sclera + episclera
• conjunctiva: lines sclera and eyelids

mid vasc (uveal tract)

• choroid (post)
• ciliary body (int)
• iris (ant)

inner nervous: retina, fovea, BV, optic disc

Question 3

Three Compartments

Answer 3

anterior chamber: anterior to iris
posterior chamber: between iris and lens
vitreous chamber: behind lens

Question 4

Three Fluids

Answer 4

blood: mostly choroidal, high flow, low desats
aq humour: watery, clear
vitreous humour: transparent jelly

Question 5

Two Segments

Answer 5

anterior: up to lens
posterior: behind lens

Question 6

Cornea

Answer 6

anterior 1/6; refraction 40D
5 layers; 0.5mm; avascular
-epithelium: regular strat squamous
-bowman's: modified stroma
-stroma: 90% thickness; collagen 
-Descements: endothelial BM
-endothelium: single layer, dehydration (pumps)

Question 7

Sclera/conjunctiva

Answer 7

sclera: 1mm thick; opaque (irregular hydrated collagen fibres
conjunctiva: translucent mucous membrane; lines sclera and eyelids
limbus: junction between cornea and sclera
lamina cribrosa: optic n/BV foramen

Question 8

Choroid

Answer 8

vascular; 0.25mm
fenestrated BV
Bruch’s membrane: external RPE; drusen
choriocapillaris: supplies RPE/outer retina

Question 9

Ciliary Body

Answer 9

aq humour, angle/humour flow, accommodation
triangular cross section
pars plicata (processes) and pars plana (ora seratta: termination of retina)

straight AP mm: widen angle for drainage
circular mm: lax zonular fibres - looser/fatter lens for accommodation
oblique mm

Question 10

Iris

Answer 10

sphincter pupillae and dilator pupillae

stroma: thin, avascular, colour, sphincter pupillae
pigment: dilator pupillae, pigment

Question 11

Retina

Answer 11

10 layers; RPE = external non-neural retina; nutrition/support
rhodopsin cycle, rods and cones, bipolar and ganglion cells

macula/fovea: avascular, central, [cones]; acuity/precision
peripheral, more rods, night vision

optic nerve: cup (

Question 12

CN III

Answer 12

midbrain (PAG)
superior cerebellum, PCA
cavernous sinus
SOF

inf div: ciliary ganglion/short nn; sphincter pupillae, IO, MR, IR
sup div: LPS, SR

Question 13

CN IV

Answer 13

dorsal midbrain (inf colliculus)
superior cb, PCA
cavernous sinus
SOF; SO

longest
contralateral (cross at midbrain)

Question 14

CN VI

Answer 14

PMJ
cavernous sinus
SOF; LR

false localisation common

Question 15

PANS (light)

Answer 15

pretectal (bilateral)
EWS, preganglionic
ciliary ganglion
short ciliary nn (superficial CN III)
sphincter pupillae

Question 16

SANS

Answer 16

hypothalamus
C8-T2 preganglionic fibres, sympathetic chain
superior cervical ganglion
long ciliary nn (alon ICA/ophth aa)
dilator pupillae

Question 17

Muscle Actions

Answer 17

RADSIN: recti adduct, superior intort

MR: adduct
LR: abduct
SR: elevation (intort, adduct)
IF: depression (extort, adduct)
SO: intort (depress, abduct)
IO: extort (elevate, abduct)

Question 18

Lens

Answer 18

65% water 35% protein; avasc
capules, nucleus, cortex, epithelium; 
epithelium: produces fibres
high protein content
nutrients from aq humour
age = compacted = thick/stiff

Question 19

CN II

Answer 19

optic nerve
optic chiasm
optic tract
optic radiation
visual cortex, FEF, association areas

superior colliculus (reflex movement)
pretectal nuclei (pupillary)
lateral geniculate (cortical relay

Question 20

functions/physiology

Answer 20

barrier: eyelids
tear film: antimicrobial
refraction: cornea, lens
nutrition: humours, choroid, RPE
IOP: humours
vision, accommodation