B7-093 Eye and Orbit Anatomy Flashcards
1
Q
what structures pass though the optic canal? [2]
A
CN II
opthalamic artery
2
Q
what structures pass through the superior orbital fissure?
A
CN III, IV, V1, and VI pass through here
3
Q
the optic canal and superior orbital fissure are located in the […] bone
A
sphenoid
4
Q
what structures pass through the inferior orbital fissure?
A
infraorbital artery and nerve
5
Q
sinus located superior to the orbit
A
frontal
6
Q
sinus located inferior to the orbit
A
maxillary
7
Q
sinus located medial to the orbit [2]
A
ethmoid
sphenoid (more posterior)
8
Q
what walls of the orbit are most susceptible to orbital blow out fractures? [2]
A
medial
inferior
9
Q
orbital contents may prolapse into the […] sinus after a blow out fracture
A
maxillary
inferior rectus muscle can become entrapped
10
Q
a patient with an orbital blow out fracture can not move the affected eye up. Why?
A
inferior rectus is entrapped in the maxillary sinus
11
Q
movements of the pupil around the vertical axis [2]
A
abduction or adduction
12
Q
movements of the pupil around the horizontal axis
A
elevation
depression
13
Q
movements of the pupil around the AP axis
A
intorsion (medial rotation)
extorsion (lateral rotation)
14
Q
opens the eye
A
levator palpebrae superioris (via CN III)
15
Q
closes the eye
A
orbicularis oculi (via CN VII)
16
Q
what CN closes the eye?
A
CN VII
17
Q
what CN opens the eye?
A
CN III
18
Q
innervates superior oblique muscle
A
CN IV
19
Q
innervates the lateral rectus muscle
A
CN VI
20
Q
abducts the eyeball
A
lateral rectus
21
Q
adducts the eyeball
A
medial rectus
22
Q
depresses, adducts, and rotates the eyeball laterally
A
inferior rectus
23
Q
elevates, adducts and rotates the eye medially
A
superior rectus
24
Q
abducts, elevates, and laterally rotates the eyeball
A
inferior oblique
25
abducts, depresses, and medially rotates the eyeball
superior oblique
26
elevates superior eyelid
levator palpebrae
27
[...] rectus elevates the eyeball
superior
28
[...] rectus depresses the eyeball
inferior
29
[...] oblique depresses the eyeball
superior
30
[...] oblique elevates the eyeball
inferior
31
both superior and inferior rectus are [...]
adductors
32
both superior and inferior obliques are [...]
abductors
33
the two muscles that have inferior in the name are [...] rotators
lateral
34
the two muscles that have superior in the name are [...] rotators
medial
35
what two muscles elevate the eye [2]
superior rectus
inferior oblique
36
what two muscles depress the eye [2]
superior oblique
inferior rectus
37
testing elevation in the abducted position isolates [...]
superior rectus
(inferior oblique is trapped)
38
testing depression in the abducted position isolates [...]
inferior rectus
(superior oblique is trapped)
39
testing depression in the adducted position isolates [...]
superior oblique
(inferior rectus is trapped)
40
testing elevation in the adducted position isolates [...]
inferior oblique
(superior rectus is trapped)
41
sensation from medial orbit to vertex of head
supratrochlear n.
42
sensation from lateral orbit to vertex of head
supraorbital n.
43
picks up sensation from orbit during infection
lacrimal n.
supratrochlear and supraorbital are sensation as well
44
innervate the nasal cavity and nasal septum [2]
anterior ethmoidal n.
posterior ethmoidal n.
45
anterior ethmoidal n. and posterior ethmoidal n. arise from
nasocilliary n.
46
sensation to the medial corner of eye
infratrochlear n.
47
provide sensation to the cornea and sclera
long and short cilliary n.
48
innervates superior oblique muscle
trochlear CN IV
49
innervates lateral rectus
abducens CN VI
50
[...] branch of occulomotor n. innervates levator palpebrae and superior rectus
superior
51
[...] branch of occulomotor n. innervates medial rectus, inferior rectus, and inferior oblique
inferior
52
parasympathetically innervates the pupil
CN III occulomotor
53
what cranial nerves travel through the cavernous sinus?
III
IV
V1
VI
54
what muscle is attached to the floor of the orbit?
inferior oblique
55
passes through the tendinous ring of the rectus muscles
optic nerve
(all the rectus muscles attach here)
56
sympathetic fibers orginate from T1-T4, run up the sympathetic chain and synapse at the [...]
superior cervical ganglion
57
located right next to the bifurcation of the internal and external carotids
superior cervical ganglion
58
sympathetic postganglionic fibers from the [...] supply the salivary gland, sweat glands, and blood vessels
external carotid plexus
59
comes off the internal carotid plexus and passes through the pterygopa ganglion to supply parasympathetic innervation to the blood vessels
deep petrosal n.
60
sympathetic postganglionic fibers from the internal carotid plexus help to [2]
dilate the pupil (dilator pupillae)
keep eyelid elevated (tarsal smooth muscle)
61
[parasympathetic/sympathetic] fibers synapse at the ciliary ganglion
parasympathetic
62
parasympathetic postganglionic fibers travel with the [...] to the spinchter pupillae and ciliary muscle
short ciliary nerves
63
parasympathetic postganglionic fibers travel with the short ciliary nerves to innervate [2]
sphinter pupillae
ciliary muscle
64
parasympathetics [...] pupil and [...] lens to provide near vision
constrict
round
65
sympathetic nerves innervate what structures of the eye [2]
dilator pupillae
superior and inferior tarsal muscles
66
how would a lesion in CN IV affect the patient's gaze?
head tilts away from affected side
diplopia worse on downward gaze
67
how would a lesion in CN VI affect the patient's gaze?
cannot look laterally with affected eye
68
how would a lesion in CN III affect the patient's gaze? [3]
down and out eye
complete ptosis
pupil dilation
69
why does an oculomotor palsy cause a down and out eye?
loss of ocular muscle innervation except SO and LR
70
why does an oculomotor palsy cause complete ptosis?
loss of innervation to levator palpebrae
71
why does an oculomotor palsy cause pupil dilation?
loss of parasympathetic innervation to pupil
72
a lesion affecting the sympathetic chain would cause?
Horner's syndrome
miosis, ptosis, anhidrosis
73
corneal reflex
afferent:
efferent:
afferent: V1
efferent: CN VII
74
layers of the eyeball
**fibrous**: sclera, cornea
**vascular**: choroid, ciliary body, iris
**inner**: retina
75
conjunctiva that lines the innermost part of the eyelids
palpebral
76
conjunctiva that lines the outermost part of the eyeball
bulbar (ocular)
77
rupture of the ciliary arteries can cause [...]
subconjunctival hemorrhage
78
increased CSF pressure would cause occlusion of what vascular structure in the eye?
1. central retinal vein (first)
2. central retinal artery
79
superior tarsal muscle is innervated by
sympathetic fibers
80
orbicularis oculi is innervated by
CN VII
81
damage of CN III will cause a [...] ptosis
complete
82
damage to the sympathetic fibers will cause [...] ptosis
partial
(like in Horner's syndrome)
83
center of vision
macula
84
area of macula most concentrated by cones
fovea
85
papilledema is caused by [...]
increased ICP
86
arterial supply to the eye is coming from [...] via [...]
internal carotid a.
via. ophthalmic a.
87
supratrochlear a. anastomoses with
facial a.
88
supraorbital a. anastomoses with
superficial temporal a.
89
the lacrimal artery anastomoses with the
middle meningeal a.
90
arteries that supply the choroid plexus [2]
anterior ciliary a.
short posterior ciliary a.
91
ophthalmic veins are valveless and can communicate directly with [...] [2]
cavernous sinus (cavernous sinus thrombosis)
pterygoid plexus of veins
92
tears come from the lacrimal gland and are washed over the eye, before entering the [...] and draining into the [...]
puncta
lacrimal canaliculi
(then lacrimal sac --> drain via nasolacrimal duct)
93
the nasolacrimal duct drains into the [...]
inferior meatus of nose
(why your nose runs when you cry)
94
tear production is done by what CN?
parasympathetics of CN VII
(via greater petrosal n., then eventually follows lacrimal n.)
95
functions of lacrimal n [2]
sensory: pain
parasympathetic: serous secretion for gland (via CN VII and greater petrosal)
96
space between the cornea and the iris/pupil
anterior chamber
97
space between the iris/pupil and the lens/ciliary body
posterior chamber
98
secretes aqueous humor
ciliary processes
99
circumferential tissue inside the eye composed of the ciliary muscle and ciliary processes
ciliary body
100
blockage of Schlemm's canal (scleral venous sinus) causes
glaucoma
101
describe the flow of aqueous humor
ciliary process --> posterior chamber --> through pupil --> anterior chamber --> drains via scleral venous sinus (Schlemm's)
102
when the ciliary muscles are relaxed, how does this effect the lens?
tension on zonular fibers of lens causes lens to be stretched for far sight
103
when the ciliary muscles contract, how does this effect the lens?
less tension on zonular fibers of the lens, lens rounds up to allow for near sight
(i.e. reading)
104
the ciliary body is innervated by [...] fibers
parasympathetic
105
allow for accommodation [3]
convergence (medial rectus)
adjust lens thickness (PSNS)
pupillary constriction (PSNS)
(used when reading)
106
rupture of [...] causes hyphema
ciliary arteries
107
blood in the anterior chamber
hyphema
108
how can hyphema lead to vision loss if left untreated?
increased intraoccular pressure can damage retina/optic nerve
109
attaches to the tarsal plate and is the primary elevator of the eyelid
levator palpebrae
110
weakness in the levator palpebrae muscle results in [...]
ptosis
(may reflect a problem with CN III)
111
the smooth muscle of the eyelid is innervated by [...] fibers
sympathetic
(damage to sympathetic fibers results in partial ptosis)
112
acts as the primary elevator of the eyeball
superior rectus
113
muscle of the iris that constricts the pupil
constrictor pupillae
(parasympathetic)
114
damage to the parasympathetic fibers results in [...] of the pupil
dilation
115
damage to the sympathetic fibers results in [...] of the pupil
constriction
116
a lesion of the abducens results in [2]
internal strabismus (medial deviation)
diplopia
117
paralysis of the medial rectus would result in
external strabismus (lateral deviation)
118
loss of visual accomodation is due to a lesion in the [...] nerve fibers to the ciliary muscle
parasympathetic
119
damage to [...] would result in inability to tightly close the eye
CN VII
120
total occlusion of the central retinal artery would result in
blindness of that eye
121
when a person is crying, what structure opens the lacrimal sac to drain the tears?
lacrimal part of the orbicularis oculi
122
opens the eyelid
levator palpebrae
123
[...] gently closes the eyelid and [...] tightly closes the eyelid
palpebral part of orbicularis oculi gently closes the eyelid and orbital part of orbicularis oculi tightly closes the eyelid
124
leads tears from the lacrimal puncta to the lacrimal sac
lacrimal canaliculi
125
which CN is an extension of the cranial meninges?
CN II
(can be used to evaluate for increased ICP)
126
between what 2 layers will a contact lens be stuck?
bulbar and palpebral conjunctiva
127
space between the iris and lens
posterior chamber
128
potential space that forms during retinal detachment
between the neural retina and pigmented retina
129
supplies the calvaria
middle meningeal artery
130
damage to [...] results in an epidural hematoma
middle meningeal artery
131
arteries that supply the skin of the face and forehead [2]
supraorbital
supratrochlear
132
supplies the nasal septum and contributes to Kesselbach's plexus
anterior ethmoidal a
133
blowout fractures usually occur [...] and [...]
medially
inferiorly
(involve maxillary)
