Ophthalmology

Question 1

what CN is the lacrimal gland supplied by

Answer 1

CN7 parasympathetic

facial

Question 2

where is aqueous humour produced

Answer 2

in the ciliary body

Question 3

how does aqueous humour get from posterior chamber to the anterior chamber

Answer 3

through the pupil via the trabecular meshwork into the canal of schlemm

Question 4

where in the anterior chamber is the aqueous humour reabsorbed

Answer 4

the iridocorneal angle

Question 5

the ophthalmic artery is a branch of which artery

Answer 5

the internal carotid

Question 6

name 2 branches of the ophthalmic artery

Answer 6

central retinal artery

posterior ciliary artery

Question 7

what is the central 2/3 of the retina supplied by

Answer 7

the central retinal artery

Question 8

what is the outer 1/3 of retina supplied by

Answer 8

the posterior ciliary artery

Question 9

where do your superior and inferior rectus muscles move your eye

Answer 9

superior rectus = up and in

inferior rectus = down and in

Question 10

where do your superior and inferior obliques move your eye

Answer 10

superior oblique = down and out

inferior oblique = up and out

Question 11

which muscle goes through the trochlear

Answer 11

superior oblique

innervated by the trochlear nerve (SO4)

Question 12

where do medial and lateral recuts muscles move your eye

Answer 12

medially and laterally osly

Question 13

what is code to remembering what nerve supplies what eye muscle

Answer 13

LR6 SO4 AO3

Question 14

in the blink reflex, what nerve conducts the AP on the sensory (afferent) limb

Answer 14

CN V1 (ophthalmic)
1st branch of the trigeminal nerve

Question 15

what are the 3 divisions of the trigeminal nerve

Answer 15

1 - ophthalmic
2 - maxillary
3 - mandibular

Question 16

in the blink reflex, what nerve conducts the AP for the motor (efferent) limb and to which muscle

Answer 16

CN 7 (facial) 
to obicularis oculi

Question 17

where do sympathetic axons exit the spinal chord

Answer 17

T1 -L2

Question 18

eye autonomics

where does the presynaptic sympathetic axons synapse

Answer 18

in the superior cervical sympathetic ganglion

Question 19

what structure do the post synaptic sympathetic axons ‘piggy back’ on

Answer 19

the internal and external carotid arteries

the ophthalmic artery carries the sympathetic fibres into orbit

Question 20

where do parasympathetic axons leave the CNS

Answer 20

craniosacral outflow

leave CNS via CN 3,7,9 & 10

Question 21

what are the long ciliary nerves supplied by

Answer 21

sympathetic

Question 22

what are he short ciliary nerves supplied by

Answer 22

sympathetic and parasympathetic

Question 23

what happens in sympathetic innervation of ciliary ganglion

Answer 23

eyes open wider
focus on far away objects
get more light into eye
emotional lacrimation

Question 24

what happens in parasympathetic innervation of the ciliary ganglion

Answer 24

stimulates obicularis oculi - makes eye more closed
focuses on near objects
lets less light in
reflex lacrimation (to clean cornea)

Question 25

what nerve supplies the afferent/sensory limb of papillary light reflex

Answer 25

CN 2 (optic)

Question 26

what nerve supplies the efferent/motor limb of papillary light reflex

Answer 26

CN 3 (oculomotor)

Question 27

what is the papillary light reflex

Answer 27

if you shine light into eye, it causes direct constriction of eye that light is being shone into and consensual constriction of the non-stimulated eye

Question 28

in between what 2 neurones does the bilateral response in the papillary light reflex occur

Answer 28

between the 2nd and 3rd neurone

Question 29

control of the lens what happens in far vision

Answer 29

``` no parasympathetics ciliary muscle relaxes ligament tightens lens flattens focus on object in distance ```

Question 30

control of the lens what happens in near vision

Answer 30

``` parasympathetics ciliary muscle contracts ligament relaxes lens becomes spherical focus on near object ```

Question 31

which CN carries the afferent/sensory limb of reflex tears

Answer 31

CN V1 (ophthalmic)

Question 32

which CN carries the efferent/motor limb of reflex tears

Answer 32

parasympathetic CN 7 (facial

Question 33

what is the vestibulooccular reflex

Answer 33

turns eyes in opposite direction of head movement stabilises gaze during movement CN III, IV, V3, VI

Question 34

what is the oculo-cardial reflex

Answer 34

reflex bradycardia in response to tension in eye muscles or pressure on eyes CNS connection between CN V1 & X

Question 35

what is horner's syndrome

Answer 35

impaired sympathetic innervation to head and neck | causes compression of cervical parts of sympathetic trunk

Question 36

where is CSF produced

Answer 36

secretory epithelium of of choroid plexus in the ventricles

Question 37

where does the choroid plexus come from

Answer 37

the 3rd, 4th and lateral ventricles

Question 38

what does CSF secretion depend on

Answer 38

the active transport of Na+, Cl- & HCO3 from across epithelium from blood to CSF

Question 39

explain the difference in ion levels between blood plasma and CSF

Answer 39

CSF has: MORE Na and Cl LESS K, glucose and protein

Question 40

what are the names of the foramen that connect the ventricles

Answer 40

lateral to 3rd = intraventricular foramen 3rd to 4th = cerebral aqueduct 4th to subarachinoid space = foramen of magendie and foramina of luschka

Question 41

how does CSF return from spinal chord to venous blood

Answer 41

via the arachinoid granulations into superior saggital sinus

Question 42

describe the cellular structure of retina

Answer 42

from anterior to posterior | ganglion cells --> bipolar cells --> photoreceptors

Question 43

what is the role of amacrine cells

Answer 43

receive input from bipolar cells | project it to ganglion and other bipolar cells

Question 44

what is the role of horizontal cells

Answer 44

receive input from photoreceptor cells | project it to other photoreceptor and bipolar cells

Question 45

explain the essence of phototransduction

Answer 45

photoreceptors have a depolarised resting membrane potential with light exposure, the photoreceptor hyperpolarizes and turns OFF basically, the presence of light causes the rod cells to hyperpolarize and turn off

Question 46

what sort of channel is the 'dark current'

Answer 46

a cGMP gated Na+ channel | open in the dark, closed in the light

Question 47

the conversion of cGMP to GMP causes the cGMP Na+ channel to open. true?

Answer 47

nope - that conversion, using PDE as the enzyme, causes the cGMP channel to close this causes the cell to hyperpolarize and turn rods OFF

Question 48

light hits the rhodopsin in rod cells 1st. true?

Answer 48

yeh - it comes in and hits 11-cis-retinal in rhodopsin this causes a conformational change to make it 11-TRANS- retinal this causes transducin to break away from rhodopsin and bind to the PDE on the rod cell

Question 49

what causes a reduction in the Ca+ and glutamate levels in phototransduction

Answer 49

hyperpolarization of the rod cell in light causes V-gated Ca+ channels to CLOSE

Question 50

what does a reduced level of glutamate cause

Answer 50

causes depolarisation of ON CENTRE bipolar cells (activates and hyperpolarization of OFF CENTRE bipolar cells (deactivates)

Question 51

what does activation of the on centre bipolar cells mean

Answer 51

the cone cells on the retina are being used to see

Question 52

what are the 3 layers surrounding the brain called

Answer 52

the meninges

Question 53

what's the name of the 3 meninges

Answer 53

from outer to inner: dura matter arachinoid matter Pia matter

Question 54

which nerve is susceptible to compression and herniation as a result of raised ICP

Answer 54

CN 3 (occulomotor)