Orbit Flashcards
1
Q
The _____coverint the eyelid is very thin and continuous with the palpebral conjunctiva
A
skin
2
Q
sparse, loose conective tissue that rarely contains fat in the eye
A
subucatneous tissue
3
Q
ciliary glands are found in what laere of the eyelid
A
subcutaneous tissue
4
Q
ciliar glands are
A
mixed sebaceous and modifies sweat glands
5
Q
Zeis glands
A
sebaceous
6
Q
Moll glands
A
modified sweat
7
Q
if the sebaceous and modifies sweat glands of the eyelid become infected, what forms
A
a sty
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
9
Q
levator palpebrae superioris muscle inserts
A
into palpebral fascia and skin of upper lid
10
Q
levator palpebrae euperioris innervated by
A
GVE fibers of oculomotor nerve (III)
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
12
Q
Ocular nerve palsy
A
complete ptosis, external strabismus, pupillary dilation
13
Q
tarsal muscle of Muller inserts on
A
tarsal plate of the upper lid
14
Q
tarsal muscle innervated by
A
postganglioinc sympathetic fibers
15
Q
tarsal muscle affected in what syndrome
A
horner;s syndrome
16
Q
cartilagineous plate tied in with the orbital septum
A
tarsus
17
Q
Horner’s syndrome involves
A
paralysis of the tarsal muscle, concomitant SLIGHT ptosis an dmiosis.
enophthalaus and anhidrosis and blushing
18
Q
the retina is an invagination of
A
diencephalon
19
Q
othe ___ formas a firewall between deep and superficial contents of the orbit
A
orbital septeum
20
Q
why is the orbital septum important
A
because the orbit is very closely related to the brain
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
22
Q
Palpebral fascia is composed of
A
tarsus and orbital septum
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
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
25
what happens if you throw off the margin of the eyelids
like when you mess up your windshield wipers. lids no longer uniformly moving across the surface of the eye
26
Continuous with periosteum at the superior and inferior orbital margins, attached to tarsal plates,
orbital septum
27
superior palpebral fascia is pierced by
levator palpebrae superioris m
28
Conjunctiva
thin membrane that lines the back of the eyelids (palpebral)and front of the eyeball (bulbar)
29
palpebral conjunctiva
is opaque and highly vascular membrane. covers posterior surface of lids,
30
bulbar conjunctiva is
transparent membrane loosely attached to the eyeball.
31
semilunar fold
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
32
why can't swelling of the lid get from upper lid to lower lid on the medial side
because of the orbital septum at the medial side.
33
what gland produces tears to keep the surface of the cornea moist
lacrial gland
34
parasympathetic innervation of lacrimal gland
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
35
Sumpathetic innervation of the lacrimal gland
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
36
lacrimal canaliculi
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
37
function of lacrimal canaliculi
drain tears from the surface of the eyeball to the superior lateral aspect to the lacrimal sac
38
lacrimal sac
elongated sac receives the lacrimal canaliculi and is continuous inferiorly with nasolacrimal duct
39
nasolacrimal duct courses through
nasolacrimal canal. and opens into inferior meatus 1cm posterior to the anterior edge of the inferior concha (drains into the nasal cavity)
40
Bony orbit comprised of what bones
frontal, zygomatic, maxilla, each are common points of fracture
41
supraorbital margin of orbit
frontal bone
| supra orbital notch
42
lateral margin of orbit
zygomatic bone, associated with orbital tubercle, the point or attachment of lateral palpebral ligament
43
infraorbital margin
zygomatic and maxilla bones
| infraorbital foramen at midpoint
44
margins are ____ than walls
thicker
45
herniation of orbital contents herniate where
maxillary sinus - here we are concerned with infection
46
fractures of the orbit can compress what structure
the optic nerve
47
Blow out fractures of the floor of the orit
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
48
Le Forte Type I
transverse fractures of the maxillae just above alveolar processes
49
Leforte Type II
pyramidal sheped fractures of maxillae usually involving part of the medial margin of one of the orbits
50
LeForte Type III aka
craniofacial dysjunction
51
Le Forte Type III
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
trauma to anterior globe pushes it through
the floor of the orbit
53
Periobita is continuous with
endocranium of middle cranial fossa (endosteal dura)
| is the periosteum of the orbit
54
endosteal dura is continusouw with
periosteal fascia, palpebral fascia and periosteum of the orbital rim
55
sheath of the optic nerve is
dura
56
meningeal dura is continuous with
sheet of the optic nerve.
57
periorbita and bulbar fascia are usu fused at optic canal and SOF, separating
the orbital cavity from the middle cranial fossa
58
bulbar sheath or fascia
covrs optic nerve and entire eyeball except cornea
59
Abducens palsy
```
increaased ICP may compress abducens nerve and result in paralysis of lateral rectus mucle
SUNDOWN GAZE (down and in)
```
60
paralysis of trochlear nerve
superior oblique
| inability to adduct and depress affected eye
61
oculomotor palsy
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
Oculomotor palsy passive sign
external strabisms
63
SO causes eye to look
down and in.
64
positions of the eye where that muscle is maximally active
cardinal signs of gaze
65
V1 Lacrimal nerve fiber type
GSA
66
V1 fontal nerve
GSA terminates as supraorbital and supratrochlear n
67
V1 nasociliary nerve
GSA nerve to eyeball
68
V1 anterior ethmoidal nerve
supplies antero superior nasal cavity and part of the outer nose
69
Corneal Reflex - nerves
in by 5, out by 7
70
```
Direct and consensual Corneal reflexes
stimulus
receptor
afferent fibers
sensory nucleus
motor nucleus
efferent fibers
effector
response
```
```
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
primary sensory nerve for the eyeball
nasociliary nerve
72
conjugate gaze
eyes move in parallel
73
the only normal disconjugate gaze
convergence - cortically mediated
74
accommodation
focusing in a near field.
| eyes converge and constrict
75
Occulomotor nerve fiber types
GSE to the extra ocular muscles
| GVE-P to ciliary muscles of lens and sphincter pupillae muscle of iris
76
ciliary ganglion fiber types
GVE-P
postganglionic sympathetic
GSA
77
Ciliary ganglion located between
lateral rectus and optic nerve
78
Cortically mediated responses that are components of accommodation
pupillary constriction and thickening of the lens
79
pupillary constriction and thickening of the lens are responses of what branch of ans
parasympathetic
80
Paralysis of oculomotor results in
external strabismus
complete ptosis
dilated and unreactive pupils
81
paralysis of trochlear results in
inability to aDduct and depress the affected eye
| pt tends to tilt his head away from the affected eye
82
paralysis of abducens nerve results in
inability to aBduct the affected eye
| diplopia due to internal strabismus
83
Chief artery of the orbit, usually the first branch of ICA
ophthalmic artery
84
arteries that supply optic nerve, what artery do they arise from
posterior ciliary a, central retinal a
| from ophthalmic artery
85
main blood supply to the retina
Central retinal artery
86
terminal branches of arteries in the retina are ______ meaning that _________,
we see these terminal branches where>
end arteries
there is not a lot of anastomotic connections
we see these with our ophthalmoscope
87
tehe central retinal artery supplies the four quadrants of the retina through
upper and lower temporal branches and upper and lower nasal branches.
88
Direct light reflex
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
Consensual light reflex
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
Direct and consensual light reflex differ in the fact that
the consensual light reflex pathway has the addition of the posterio r commisure to get the reflex
91
important structrual components of the pupillary light reflex
pretectum and the posterior commisure
92
pathway for direct light reflex
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
pathway for indirect light reflex
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
pupillary dilation response
decrease in amount of light reaching retina results in bilateral reflex diction of the pupils
95
pupillary dilation response mediated through
brainstem and upper spinal cord
96
horner;s sydrome
interruption of the pupillary dilation response. characterized by ipsilateral pupillary constriction, slight ptosis and anhydrous and blushign
97
pupilary dilation response path
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
Triad of accomodation
convergence of gaze
pupillary constriction
thickening of the lens
99
Accommodation is a ______ mediated response
cortically mediated
| from frontal eye field of frontal lobe and projects to the midbrain
100
is accommodation a reflex
no
101
Accommodation is the only naturally occurring_____gaze
disconjugate
102
Accommodation path
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
Pretectum is a critcal link
direct light response
104
ILCC at T1 is a critical link
pupillary dilation
105
cortically mediated response
accomodation
106
posterior commissure
consensual light reflex
107
horners syndrom
pupillary dilation
108
convergence of gaze, pupillary constriction, thickening of lens
triad of accommodation
109
in by two out by 3
pupillary response
110
in by 2 out by sympathetic branch of ciliary ganglion from SCG
pupillary dilation
111
corticotectal fibers and edinger wetphal and oculomotor nuclei
accomodation
112
Argyll Robertson pupil aka
prostitutes sign
113
argyll robertson pupil definition
accommodating but unreactive
114
argyll robertson pupil cause
syphilis infection
| due to destruction of pretectum (important in light reflex but not in accommodation)
115
the pretectum is important in ______ but not in ______
light reflex, but not in accomodation
116
Holmes Adie pupil aka
tonic adie pupil
117
Holmes Adie pupil definition
benign condition which may be due to lesion of ciliary ganglion
slow constriction on convergence
118
Homes aide pupil and parasympathomimetic drus
parasympathomimetic drugs constrict the tonic pupil - no effect on normal pupil
119
papilledema
Increased ICP restricts venous return from the retina
| the concomitant increase in venous pressure results in edema or swelling of the optic disc
