ANATOMY

Question 1

white part of eye?

Answer 1

sclera = POSTERIOR 5/6

Question 2

3 layers of eye? order

Answer 2

out 
fibrous coat 
vascular coat 
sensory coat 
in

Question 3

iris part of eye gives what?

function

Answer 3

coloured part of eye

controls diameter of pupil
and controls amount of light entering eyeball

Question 4

3 parts of vascular part?

Answer 4

ciliary body
iris
choroid

Question 5

cornea?

Answer 5

anterior 1/6 of eye which is transparent and allows light into eyeball

Question 6

choroid function?

Answer 6

supplies blood to outer layers of retina by diffusion

Question 7

what does retina contain?

Answer 7

has light sensitive rods and cones which enables us to see

Question 8

what is lens suspended by and from what?

Answer 8

suspended by suspensory ligaments from ciliary body

Question 9

purpose of aqueous humour?

Answer 9

maintains intraocular pressure

Question 10

prrpose of vitreous humour?

Answer 10

helps cushion the retina

Question 11

chamber of anterior segment?

Answer 11

anterior chamber - in front of iris

posterior chamber - behind iris but infront of lens

Question 12

how does AH flow?

Answer 12

from posterior chamber to anterior chamber

through angle of anterior chamber and trabecular meshwork
and then through schlemms canal

Question 13

what glands present on eyelashes?

Answer 13

sebaceous glands

Question 14

conjunctivae?

what does it not cover?

Answer 14

thin vascular membrane that covers inner surface of eyelids and loops back over sclera

not covering cornea

Question 15

lacrimal gland?

innervation

Answer 15

situated in orbit laterally

parasympathetic from facial nerve

Question 16

innervation of ciliaris?

Answer 16

parasympathetic - constrict

Question 17

innervation of dilator papillae?

Answer 17

sympathetic

Question 18

position of oblique muscles of eye?

Answer 18

superior - from roof of orbit posteriorly

inferior - floor of orbit anteriorly

Question 19

how do the recti and oblique muscles insert onto eye?

Answer 19

recti - anteriorly onto sclera

oblique - posteriorly onto sclera

Question 20

extra muscle of eye called?

Answer 20

LPS - lever palpebrae superioris

Question 21

innervation of eye muscles?

Answer 21

SO - trochlear nerve
LR - abducent nerve

everything else - occulomotor

Question 22

optic nerve of eye does what?

Answer 22

carries visual impulse from eyeball to brain etc

Question 23

oculomotor nerve of eye?
fibers type
pathway?

Answer 23

innervates all eye muscles except two and carries parasympathetic fibers

flows to synapse at ciliary ganglion in orbit

Question 24

what artery supplies orbit?

Answer 24

ophthalmic artery branch of ICA

Question 25

central retinal artery?

Answer 25

branch of ophthalmic artery - supplies inner layers of retina

Question 26

short posterior ciliary arteries?

Answer 26

branches of ophthalmic artery - supply posterior part of choroid and outer retina

Question 27

long posterior ciliary arteries?

Answer 27

branches of ophthalmic artery - supply anterior part of choroid, ciliary body, iris

Question 28

innervation of eye includeS?

Answer 28

sensory motor autonomic

Question 29

sensory innervation of eye by?

Answer 29

CN V1

Question 30

any blood vessels in cornea?

Answer 30

no vascularity here

Question 31

name of basement membranes in cornea?

Answer 31

bowman descemets

Question 32

cornea transplant why is avascularity key?

Answer 32

rejection of transplant is unlikely - less matching is needed here

Question 33

glaucoma?

Answer 33

where angle is closed and AH not drained and intraocular pressure increases in eye leading to blindness

Question 34

fovea centralis?

Answer 34

cones and no rods packed with cones and so max visual acuity centre part of fovea

Question 35

cataract is opacification where?

Answer 35

on LENS

Question 36

macula?

Answer 36

more cones than rods

Question 37

function of tears?

Answer 37

keeps cornea moist washes away foreign bodies provides smooth surface for refraction of light

Question 38

3 layers of tear film?

Answer 38

inner/deep - mucinous layer aqueous layer - water outer/superifical - oily layer

Question 39

blinking does what to tear film?

Answer 39

distributes tear filme evenly

Question 40

what happens to tear film with eyes open? | and triggers to blink

Answer 40

aqueous component of tears begin to evaporate and oily layer is getting closer to the mutinous layer when these 2 layers touch it triggers to blink

Question 41

how does light move in eye?

Answer 41

light waves bend at cornea but more so at lens to form clear image on retina

Question 42

close up objects therefore? | lens

Answer 42

lens is thicker and constricts more | as need to bend light more

Question 43

accommodation of eye?

Answer 43

ability to focus on far off or near objects by changing how much we need to bend light

Question 44

what causes lens to contract? | innervated by?

Answer 44

ciliary body contraction by parasympathetic innervation makes lens thicker

Question 45

what happens to eyes when close up object?

Answer 45

converge

Question 46

name all extrinsic muscles of eye?

Answer 46

``` MEDIAL RECTUS LATERAL RECTUS INFERIOR RECTUS SUPERIOR RECTUS SUPERIOR OBLIQUE INFERIOR OBLIQUE ```

Question 47

MYOPIA? explain issue treatment

Answer 47

short -sight see close up not far off -2/-3 etc rays focus before retina - bending power too much use of biconcave lens to correct and reduce bending power

Question 48

hyperopia? explain issue treatment

Answer 48

long sighted see far off not close up +2/+3 rays formed behind retina use of biconvex lens to elevate bending power

Question 49

convergent squint in person means?

Answer 49

hyperopia

Question 50

astigmatism? explain physiology treatment

Answer 50

close up and far off are hazy due to surface having different curvature in different areas cylindrical glasses - one curve on axis measured in degrees & numbers seperetaly

Question 51

what in the eye generates AP?

Answer 51

rods and cones triggered by visible light

Question 52

lamellae of rods contain?

Answer 52

visual pigment rhodopsin in the cell membrane

Question 53

lamellae of cones contain?

Answer 53

cone OSPINS O, M, L | WHICH DIFFER IN THEIR SPECTRAL SENSITIVITY

Question 54

HOW DOES LIGHT ONTO visual pigments in the rods and cones result in action potential?

Answer 54

1.light onto rods/cones 2.opsin protein in them have vitamin A structure called 11 cis retinal 3. it is converted to all-trans retinal cell changes shape all-trans retinal bleaches pigment lead to hyperpolaristaion and impulse transmitted and ap created

Question 55

phototrasnduction?

Answer 55

where light is converted into electrical impulses

Question 56

role of vitamin A in the visual pigment?

Answer 56

visual pigment regeneration - RECYCLE OF CIS RETINOL - to reform opsin

Question 57

vitamin A deficiency?

Answer 57

will affect vision | needed for healthy epithelium

Question 58

vitamin A deficiency signs?

Answer 58

triangle spots in conjunctivae | corneal ulcers

Question 59

where is trans-retinol converted into cis retinol?

Answer 59

in RPE -

Question 60

visual field test?

Answer 60

use of finger to test fuel of vision

Question 61

visual acuity test?

Answer 61

use of snellens chart

Question 62

how do fibres run in the eye?

Answer 62

1. from eye through optic nerve 2. through optic chiasma 3. medial fibers cross here to opposite side 4. through optic tract 5. synapse at LGB of thalamus 6. from here optic radiation to reach primary visual cortex in occipital lobe

Question 63

optic chiasma lesion lead to?

Answer 63

bitemporal hemianopia

Question 64

optic tract/radiation lesion lead to?

Answer 64

contralateral homonymous hemianopia