Anatomy

Question 1

name the 7 bones of the orbit

Answer 1

frontal

zygomatic

maxilla

nasal

sphenoid

ethmoid

lacramal

Question 2

which bone does the optic canal pass through?

Answer 2

sphenoid

Question 3

in addition to the optic canal the sphenoid bone also contains what?

Answer 3

superior orbital fissure

Question 4

what is the apex?

Answer 4

the optic canal

Question 5

the roof, medial and lateral walls and the floor of the orbit make up the what?

Answer 5

orbital margins

Question 6

the superior/inferior orbital margin is more anterior

Answer 6

superior orbital margin

(slopes forward with inferior more posterior)

Question 7

trauma to the orbit results in what?

Answer 7

orbital blowout fracture

NOTE: bony rim protected but force travels to floor and fractures

Question 8

when an orbital blowout fracture occur what can also be damaged?

Answer 8

intraorbital nerves- sensory to face (maxilla and wings of nose)

Question 9

fractured zygoma tends to rotate which direction?

Answer 9

medially

Question 10

the suspensory ligament of the eye attaches to what?

Answer 10

the zygoma laterally

Question 11

if zygoma fractures and suspensory ligament drops what clinical sign can occur?

Answer 11

diplopia- double vision

Question 12

what are the two parts of the eyelid that make up the orbicularis oculi muscle

Answer 12

orbital- around eye

palpebral- eyelid itself

Question 13

what helps prevent spread of infection from superficial to deep in the eye?

Answer 13

orbital septum- sheet of fascia

Question 14

what gland containing sturcture lies within the upper eyelid?

Answer 14

superior tarsus- tarsal glands embedded in tarsi

Question 15

what is the limbus?

Answer 15

corneoscleral junction

Question 16

what is the function of the conjuctiva?

Answer 16

forms defensive barrier to foreign bodies penetrating deep to it into the orbit

Question 17

defien tarsus

Answer 17

dense connective tissue bands in half moon shape that give shape to the eyelid- superior/inferior

Question 18

what is the name of the tendon attached to the superior tarsus responsible for lifting the eyelid?

Answer 18

levator palpebrae superioris

Question 19

what is known as mullers muscle?

Answer 19

superior tarsal muscle attached to superior tendon that helps to lift the eyelid

Question 20

glands in the tarsus secrete what?

Answer 20

lipids for lubraication

prevents tears overflowing in normal day to day life until youre actually crying

Question 21

what nerve innervates teh lacrimal gland responsible for producing lacriaml fluid?

Answer 21

parasympathetic CNVII

Question 22

describe the lacrimal apparauts

Answer 22

lacrimal gland produces lacrimal fluid

washes over eye towards medial angle

drained through lacrimal puncta

then canaliculi into lacriaml sac

finally drain into nasolacrimal duct

Question 23

what are the three layers of the eye?

Answer 23

fibrous

uvea

retina

Question 24

what are the two parts of the fibrous layer of the eye?

Answer 24

sclera

cornea

Question 25

what makes up the uvea?

Answer 25

**iris** **ciliary body**- controls iris and aqueous humor secretion **choriod**- nutrition and gas exchange

Question 26

the anterior/posterior segment of the eye is divided into chambers?

Answer 26

anterior segment divided into anterior/posterior chambers

Question 27

where is the anterior chamber located?

Answer 27

between cornea and iris

Question 28

where is the posterior chamber located?

Answer 28

between iris and suspensory ligaments

Question 29

the anterior and posterior chambers contain what?

Answer 29

aqueous humour

Question 30

the posterior segment of the eye is located where?

Answer 30

behind the lens- post 2/3rds

Question 31

he posterior segment of teh eye contains what?

Answer 31

**vitreous body**- vitreous humour

Question 32

vitreous body is common location for what pathology?

Answer 32

floaters

Question 33

a clouding of the lens is known as what?

Answer 33

cataract

Question 34

the ciliary body secretes what?

Answer 34

aqueous

Question 35

describe the circulation of aqueous

Answer 35

circulates within posterior chamber passes through the pupil into anterior chamber aqueous reabsorbed into canal of schlemm

Question 36

from which artery does the opthalmic artery arise?

Answer 36

internal carotid artery

Question 37

through what stucture do the cnetral arerty and vein of the retina pass through?

Answer 37

optic nerve

Question 38

what kind of artery is the central artery of the retina?

Answer 38

**end artery**- only one supplying tissue

Question 39

the inferior opthalmic vein drains mainly into which vein?

Answer 39

superior opthalmic vein

Question 40

the fundus includes what structures?

Answer 40

optic dsc macula fovea

Question 41

the optic disc is the point of which nerve formation?

Answer 41

CN II

Question 42

which structure ahs eh greatest density of cones?

Answer 42

macula

Question 43

where is the fovea located?

Answer 43

centre of the macula- area of most acute vision

Question 44

the optic disc is also the ____ \_\_\_

Answer 44

blind spot

Question 45

name the retina layers from posterior to anterior

Answer 45

photoreceptors ganglion cells axons of ganglion cells

Question 46

why is the optic disc a blind spot?

Answer 46

there are no photoreceptors in the ooptic disc

Question 47

the retinal veins and arteries lie anterior to the retina true/false?

Answer 47

true

Question 48

the retina is divided up how?

Answer 48

upper and lower nasal/temporal quadrants

Question 49

complete interruption of flow of teh central artery or vein will result in what?

Answer 49

monocular blindness

Question 50

complete interruption of flow in a retinal arter branch/retinal vein will result in what?

Answer 50

loos of an area of visual field corresponding to area of ischameia

Question 51

light from objects in the right visual field is processed by the left primary visual cortex true/flase

Answer 51

true, light processed by opposite visual cortex NOTE: light from objects in upper visual field processed in lower cortex and vice versa

Question 52

name the 7 extraocular muscles

Answer 52

superior rectus inferior rectus medial rectus lateral rectus superior oblique inferioroblique levator palpebrae superioris

Question 53

the rectus muscles all originate from where?

Answer 53

common tendinous ring

Question 54

extracolular msucles insert where?

Answer 54

onto the sclera

Question 55

what is the somatic innervation of the extraocular muscles?

Answer 55

**LR6 SO4 AO3** lateral rectus- CN VI superior oblique- CN IV all others- CN III

Question 56

most musclehave a secondary movement apart from which ones?

Answer 56

medial and lateral rectus

Question 57

lateral rectus can only _____ the eyeball

Answer 57

abduct

Question 58

in clinical testing of eye movement what do you have to do in order to test an individual eye muscle?

Answer 58

have to line up gaze with the muscle being tested

Question 59

when in abduction SR can only ______ the eyeball

Answer 59

elevate

Question 60

when in abduction the IR can only ______ the eyeball

Answer 60

depress

Question 61

medial rectus can only _____ the eyeball

Answer 61

adduct

Question 62

when in adduction IO can only ______ the eyeball

Answer 62

elevate

Question 63

when in adduction the SO can only _____ the eyeball

Answer 63

depress

Question 64

describe pure elevation and the action of the muscles involved (synergistic or antagonists)

Answer 64

SR and IO **synergistically** elevate eyes **antagonists** as rotators **pure elevation**

Question 65

describe pure depression and the actions of the muscles involved? (synergistic/antagonists)

Answer 65

SO and IO **synergistically** depress eyes **antagonist**s as adductors/abductors **pure depression**

Question 66

which sensory nerve innervates each of the coloured areas?

Answer 66

purple- ophthalmic nerve CN V1 blue- maxillary nerve CN V2 pink- mandibular nerve CN V3

Question 67

blink reflex is also known as what?

Answer 67

corneal refelx

Question 68

which of sensory and motor neurones are afferent/efferent?

Answer 68

sensory = afferent motor = efferent

Question 69

APs from the cornea are conducted via what?

Answer 69

CN V1 branches

Question 70

in the corneal reflex, central CNS connections are made between what?

Answer 70

CN V and CN VII

Question 71

motor APs in the corneal reflex are conducted via what to the eyelid?

Answer 71

CN VII

Question 72

skin provides sympathetic innervation of what?

Answer 72

arterioles of teh head sweat glands arrector muscles

Question 73

descirbe the route of sympatheic axons

Answer 73

originates in autonomic centre of brain exits spinal cord with **T1-L2** spinal nerves travel to sympatheic chains and pass into all spinal nerves pass into splanchnic nerves to suplly organs

Question 74

presynaptic sympathetic axons from CNS exit spinal cord level \_\_\_

Answer 74

T1

Question 75

post-synaptic sympathetic axons enter internal and externla carotid nerves before passing onto the surface of what?

Answer 75

internal and external carotid arteries

Question 76

which artery carries sympathetic axons to the orbit?

Answer 76

opthalmic artery

Question 77

all parasympathetic nerves leave the CNS via which cranial nerves?

Answer 77

III, VII, IX, X via sacral spinal nerves

Question 78

CN III passes through the ______ \_\_\_ before exiting through what?

Answer 78

passes through **cavernous sinus** before exiting via **superior orbital fissure**

Question 79

ciliary nerves control what?

Answer 79

diameter of iris and refractive shape of the lens

Question 80

what are long and short ciliary nerves?

Answer 80

long- sympathetic, somatic sensory short- sympathetic, parasympathetic

Question 81

long/short ciliary nerves form first part of blink relfex

Answer 81

long ciliary nerves

Question 82

what is the accomodation reflex?

Answer 82

docussing lens far & near

Question 83

vestibulo-ocular reflex deos what?

Answer 83

turns eyes in opposite direction to a head movement stabilizing gaze on a object during movement

Question 84

descirbe the oculocardiac reflex

Answer 84

reflex bradycardia in response to tension on teh extraocular muscles or pressure on the eye

Question 85

the levator palpebrae superioris contains skeletal and smooth muscle true/false?

Answer 85

true

Question 86

what class of drug dilate the pupil?

Answer 86

mydriatic drugs Note; a non-physiologically enlarged pupill is a mydriatic pupil

Question 87

how are dilator pupillae fibres arranged?

Answer 87

radially originating around external circumference of the iris

Question 88

what is a miotic pupil?

Answer 88

a non-physiologically constricted pupil N.B. compomnent of horners syndrome

Question 89

a fixed 'pin point' pupil is a serious sign and can be seen in?

Answer 89

opiate drugs

Question 90

a 'fix-dilated' or blown pupil can be seen in what cranial nerve pathology?

Answer 90

CN III pathology

Question 91

the sensory (afferent) limb of teh light reflex is ipsilateral/bilateral?

Answer 91

sensory (afferent) = ipsilateral motor (efferent) = bilateral

Question 92

the pupillary light reflex is a how many neurone chain?

Answer 92

4

Question 93

describe the 4 neurones involved in the pupillayr light reflex

Answer 93

1. retinal, passes via ipsilateral optic nervesynapsing in pretectal nucleus in midbrain 2. connect pretectal nucleus to synapse in Edinger- westphal nucleus (bilateral) 3. pass from EW via CN III synapsing in ciliary ganglion (bilateral) 4. ciliary nerves to sphincter pupillae muscles (bilateral)

Question 94

the ciliary muscle relaxes in near/far vision?

Answer 94

relaxes in far vision constracts in near vision

Question 95

what are the three clinically assessed components of the accomodaion reflex?

Answer 95

bilateral pupillary constriction bilateral convergence of eyes to midline bilateral relaxation of lens

Question 96

the lens is flattened in near/far vision?

Answer 96

far vision

Question 97

what are the three forms of tear?

Answer 97

basal reflex emotional

Question 98

horners syndrome is a result of impairede ______ innervation to head and neck

Answer 98

impaired sympathetic innervation

Question 99

what fibres encircle the pupil?

Answer 99

sphincter pupillae fibres

Question 100

what muscle is respsonsible for relaxing and tightenong the lens?

Answer 100

ciliary muscle