Orbit Flashcards

1
Q

The _____coverint the eyelid is very thin and continuous with the palpebral conjunctiva

A

skin

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2
Q

sparse, loose conective tissue that rarely contains fat in the eye

A

subucatneous tissue

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3
Q

ciliary glands are found in what laere of the eyelid

A

subcutaneous tissue

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4
Q

ciliar glands are

A

mixed sebaceous and modifies sweat glands

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5
Q

Zeis glands

A

sebaceous

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6
Q

Moll glands

A

modified sweat

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7
Q

if the sebaceous and modifies sweat glands of the eyelid become infected, what forms

A

a sty

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8
Q

Orbicularis occuli has two portions

A

palpebral potion and lacrimal portion.
palpebral - integrated with levitator palpebrae superiors
lacrimal - extends from posterior lacrimal crest to the tarsal plates of lids and lacrimal sac, increases the amount of lid contact to the suface of the eyeball

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9
Q

levator palpebrae superioris muscle inserts

A

into palpebral fascia and skin of upper lid

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10
Q

levator palpebrae euperioris innervated by

A

GVE fibers of oculomotor nerve (III)

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11
Q

destruction of the oculomotor nerve or one of its branches to levitator palpebrae superiorisresults in

A

paralysis of this muscle and COMPLETE ptosis

This is ocular nerve palsy

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12
Q

Ocular nerve palsy

A

complete ptosis, external strabismus, pupillary dilation

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13
Q

tarsal muscle of Muller inserts on

A

tarsal plate of the upper lid

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14
Q

tarsal muscle innervated by

A

postganglioinc sympathetic fibers

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15
Q

tarsal muscle affected in what syndrome

A

horner;s syndrome

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16
Q

cartilagineous plate tied in with the orbital septum

A

tarsus

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17
Q

Horner’s syndrome involves

A

paralysis of the tarsal muscle, concomitant SLIGHT ptosis an dmiosis.
enophthalaus and anhidrosis and blushing

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18
Q

the retina is an invagination of

A

diencephalon

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19
Q

othe ___ formas a firewall between deep and superficial contents of the orbit

A

orbital septeum

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20
Q

why is the orbital septum important

A

because the orbit is very closely related to the brain

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21
Q

when we suffer traumatic facial injure what do we care about repairing first

A

want to line up the teeth and the orbit

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22
Q

Palpebral fascia is composed of

A

tarsus and orbital septum

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23
Q

What do the tarsal glands secrete, and why is ti important

A

an oily secretion which helps to resist the overflow of tears at the palpebral margin

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24
Q

tarsus

A

comprised of two dense fibrous connective tissue plates in the upper and lower margins of the lids.
both are attached to the medial and lateral palpebral ligaments, and are semilunar shaped in order to conform the curvature of the eyeball

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25
Q

what happens if you throw off the margin of the eyelids

A

like when you mess up your windshield wipers. lids no longer uniformly moving across the surface of the eye

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26
Q

Continuous with periosteum at the superior and inferior orbital margins, attached to tarsal plates,

A

orbital septum

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27
Q

superior palpebral fascia is pierced by

A

levator palpebrae superioris m

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28
Q

Conjunctiva

A

thin membrane that lines the back of the eyelids (palpebral)and front of the eyeball (bulbar)

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29
Q

palpebral conjunctiva

A

is opaque and highly vascular membrane. covers posterior surface of lids,

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30
Q

bulbar conjunctiva is

A

transparent membrane loosely attached to the eyeball.

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31
Q

semilunar fold

A

crescent shaped membranous fold formed by the bulbar conjunctiva t the MEDIAL can thus. forms the lateral border of the triangularly shaped lacrimal lake at the center of which is the lacrimal carunck

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32
Q

why can’t swelling of the lid get from upper lid to lower lid on the medial side

A

because of the orbital septum at the medial side.

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33
Q

what gland produces tears to keep the surface of the cornea moist

A

lacrial gland

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34
Q

parasympathetic innervation of lacrimal gland

A

superior salivatory nucleus–> facial nerve–> freater superficial petrosal nerve and vidian nerve –> sphenopalatine ganglion

post ganglionic parasympathetic fivers course via maxillary, zygomatic and lacrimal nerves

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35
Q

Sumpathetic innervation of the lacrimal gland

A

post ganglionic sympathetic fibers from superior cervical ganglion, –> internal carotid plexus–> deep petrosal nerve, –> fuses with greater superficial petrosal to form vidian nerve–> through sphenopalatine ganglion and distribute to lacrimal gland via maillary zygomatic lacrimal nerve route.

may even reach it in lacrimal plexus in adventitia of lacrimal artery

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36
Q

lacrimal canaliculi

A

small L shaped tube located at the palpebral margins of each led at the medial canthus. The two canaliculi straddle the posterio aspect of the medial palpebral ligament

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37
Q

function of lacrimal canaliculi

A

drain tears from the surface of the eyeball to the superior lateral aspect to the lacrimal sac

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38
Q

lacrimal sac

A

elongated sac receives the lacrimal canaliculi and is continuous inferiorly with nasolacrimal duct

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39
Q

nasolacrimal duct courses through

A

nasolacrimal canal. and opens into inferior meatus 1cm posterior to the anterior edge of the inferior concha (drains into the nasal cavity)

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40
Q

Bony orbit comprised of what bones

A

frontal, zygomatic, maxilla, each are common points of fracture

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41
Q

supraorbital margin of orbit

A

frontal bone

supra orbital notch

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42
Q

lateral margin of orbit

A

zygomatic bone, associated with orbital tubercle, the point or attachment of lateral palpebral ligament

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43
Q

infraorbital margin

A

zygomatic and maxilla bones

infraorbital foramen at midpoint

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44
Q

margins are ____ than walls

A

thicker

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45
Q

herniation of orbital contents herniate where

A

maxillary sinus - here we are concerned with infection

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46
Q

fractures of the orbit can compress what structure

A

the optic nerve

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47
Q

Blow out fractures of the floor of the orit

A

may be due to trauma to the front of the eyeball or a depressed fracture of the zygomatic bone, which is displaced medially
cause herniation of certain orbital structures into maxillary sinus

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48
Q

Le Forte Type I

A

transverse fractures of the maxillae just above alveolar processes

49
Q

Leforte Type II

A

pyramidal sheped fractures of maxillae usually involving part of the medial margin of one of the orbits

50
Q

LeForte Type III aka

A

craniofacial dysjunction

51
Q

Le Forte Type III

A

extensive tranverse fractures of face involving many facial bones and both orbits. basically the face has been separated from th ease of the skull

52
Q

trauma to anterior globe pushes it through

A

the floor of the orbit

53
Q

Periobita is continuous with

A

endocranium of middle cranial fossa (endosteal dura)

is the periosteum of the orbit

54
Q

endosteal dura is continusouw with

A

periosteal fascia, palpebral fascia and periosteum of the orbital rim

55
Q

sheath of the optic nerve is

A

dura

56
Q

meningeal dura is continuous with

A

sheet of the optic nerve.

57
Q

periorbita and bulbar fascia are usu fused at optic canal and SOF, separating

A

the orbital cavity from the middle cranial fossa

58
Q

bulbar sheath or fascia

A

covrs optic nerve and entire eyeball except cornea

59
Q

Abducens palsy

A
increaased ICP may compress abducens nerve and result in paralysis of lateral rectus mucle
SUNDOWN GAZE (down and in)
60
Q

paralysis of trochlear nerve

A

superior oblique

inability to adduct and depress affected eye

61
Q

oculomotor palsy

A

complete ptosis,
inability to abduct and elevate eye (SR)
inability to adduct affected eye (MR)
inability to abduct and dprese affected eye(IR)
inability to adduct and elevate affected eye (IO)

62
Q

Oculomotor palsy passive sign

A

external strabisms

63
Q

SO causes eye to look

A

down and in.

64
Q

positions of the eye where that muscle is maximally active

A

cardinal signs of gaze

65
Q

V1 Lacrimal nerve fiber type

A

GSA

66
Q

V1 fontal nerve

A

GSA terminates as supraorbital and supratrochlear n

67
Q

V1 nasociliary nerve

A

GSA nerve to eyeball

68
Q

V1 anterior ethmoidal nerve

A

supplies antero superior nasal cavity and part of the outer nose

69
Q

Corneal Reflex - nerves

A

in by 5, out by 7

70
Q
Direct and consensual Corneal reflexes 
stimulus
receptor
afferent fibers
sensory nucleus
motor nucleus
efferent fibers
effector
response
A
protective reflex
lightly touching cornea
nakedd nerve endings in cornea
nasociliary nerve, especially long ciliary nerves
descending nucleus of V
facial nucleus
facial nerve
orbicularis oculi muscle
blinking (both direct and consensual
71
Q

primary sensory nerve for the eyeball

A

nasociliary nerve

72
Q

conjugate gaze

A

eyes move in parallel

73
Q

the only normal disconjugate gaze

A

convergence - cortically mediated

74
Q

accommodation

A

focusing in a near field.

eyes converge and constrict

75
Q

Occulomotor nerve fiber types

A

GSE to the extra ocular muscles

GVE-P to ciliary muscles of lens and sphincter pupillae muscle of iris

76
Q

ciliary ganglion fiber types

A

GVE-P
postganglionic sympathetic
GSA

77
Q

Ciliary ganglion located between

A

lateral rectus and optic nerve

78
Q

Cortically mediated responses that are components of accommodation

A

pupillary constriction and thickening of the lens

79
Q

pupillary constriction and thickening of the lens are responses of what branch of ans

A

parasympathetic

80
Q

Paralysis of oculomotor results in

A

external strabismus
complete ptosis
dilated and unreactive pupils

81
Q

paralysis of trochlear results in

A

inability to aDduct and depress the affected eye

pt tends to tilt his head away from the affected eye

82
Q

paralysis of abducens nerve results in

A

inability to aBduct the affected eye

diplopia due to internal strabismus

83
Q

Chief artery of the orbit, usually the first branch of ICA

A

ophthalmic artery

84
Q

arteries that supply optic nerve, what artery do they arise from

A

posterior ciliary a, central retinal a

from ophthalmic artery

85
Q

main blood supply to the retina

A

Central retinal artery

86
Q

terminal branches of arteries in the retina are ______ meaning that _________,
we see these terminal branches where>

A

end arteries
there is not a lot of anastomotic connections
we see these with our ophthalmoscope

87
Q

tehe central retinal artery supplies the four quadrants of the retina through

A

upper and lower temporal branches and upper and lower nasal branches.

88
Q

Direct light reflex

A

elicited by shining a bright light in an eye resulting in ipsilateral pupillary constriction, which is mediated at the level of the brainstem via the parasympathetics

89
Q

Consensual light reflex

A

shining a bright light in one eye will result in pupillary constriction of the contralateral eye
degree of constriction may be less than that in the ipsilateral eye.

90
Q

Direct and consensual light reflex differ in the fact that

A

the consensual light reflex pathway has the addition of the posterio r commisure to get the reflex

91
Q

important structrual components of the pupillary light reflex

A

pretectum and the posterior commisure

92
Q

pathway for direct light reflex

A

retina–>optic nerve–> optic tract–>brachium of superior colliculuc–> superior colliculus–>pretectum–>edinger westphal nucleus–> oculomotor nerve–> ciliary ganglion–> pupillary constrictor muscle–> ipsilateral pupillary constriction

93
Q

pathway for indirect light reflex

A

retina–> optic nerve–> optic tract–>brachim of superior colliculus–>superior colliculus–> pretectum–> POSTERIOR COMMISURE–> opposite side edinger westphal nucleus–> opposite oculomotor nerve–> opposite ciliary ganglion–> pupilary constrictor muscles–> contralateral pupilary constrition

94
Q

pupillary dilation response

A

decrease in amount of light reaching retina results in bilateral reflex diction of the pupils

95
Q

pupillary dilation response mediated through

A

brainstem and upper spinal cord

96
Q

horner;s sydrome

A

interruption of the pupillary dilation response. characterized by ipsilateral pupillary constriction, slight ptosis and anhydrous and blushign

97
Q

pupilary dilation response path

A

decreased light–> retina–>optic nerve–>superior colliculus–> pretectum–>reticular fromation–> lateral reticulospinal tract–> preganglionic sympathetic neruons at T1–> back to head –> superior cervical ganglion–> pupillary dilator muscles

response is pupillary dilation

98
Q

Triad of accomodation

A

convergence of gaze
pupillary constriction
thickening of the lens

99
Q

Accommodation is a ______ mediated response

A

cortically mediated

from frontal eye field of frontal lobe and projects to the midbrain

100
Q

is accommodation a reflex

A

no

101
Q

Accommodation is the only naturally occurring_____gaze

A

disconjugate

102
Q

Accommodation path

A

frontal eye field–> corticotectal fibers–> superior colliculus–> edinger westphal and oculomotor nucleus

edinger westphal–> ciliary ganglion –> pupillary constriction and thickening of lens

oculomotor nucleus–> convergence of gaze (dysconjugate gaze)

103
Q

Pretectum is a critcal link

A

direct light response

104
Q

ILCC at T1 is a critical link

A

pupillary dilation

105
Q

cortically mediated response

A

accomodation

106
Q

posterior commissure

A

consensual light reflex

107
Q

horners syndrom

A

pupillary dilation

108
Q

convergence of gaze, pupillary constriction, thickening of lens

A

triad of accommodation

109
Q

in by two out by 3

A

pupillary response

110
Q

in by 2 out by sympathetic branch of ciliary ganglion from SCG

A

pupillary dilation

111
Q

corticotectal fibers and edinger wetphal and oculomotor nuclei

A

accomodation

112
Q

Argyll Robertson pupil aka

A

prostitutes sign

113
Q

argyll robertson pupil definition

A

accommodating but unreactive

114
Q

argyll robertson pupil cause

A

syphilis infection

due to destruction of pretectum (important in light reflex but not in accommodation)

115
Q

the pretectum is important in ______ but not in ______

A

light reflex, but not in accomodation

116
Q

Holmes Adie pupil aka

A

tonic adie pupil

117
Q

Holmes Adie pupil definition

A

benign condition which may be due to lesion of ciliary ganglion
slow constriction on convergence

118
Q

Homes aide pupil and parasympathomimetic drus

A

parasympathomimetic drugs constrict the tonic pupil - no effect on normal pupil

119
Q

papilledema

A

Increased ICP restricts venous return from the retina

the concomitant increase in venous pressure results in edema or swelling of the optic disc