export_nbeo anatomy Flashcards
(237 cards)
1
Q
what is telecanthus?
A
abonormally wide distance between medial canthi
2
Q
which cranial nerve palsy can cause ectropion?
A
VII
3
Q
which portion of the orbicularis muscle is used for reflex blinking?
A
palpebral
4
Q
which portion of the orbicularis muscle is used for forced blinking?
A
orbital
5
Q
what muscle keeps the eyelid tight against the globe?
A
muscle of riolan part of the palpeberal portion of the orbicularis
6
Q
what is the function of the orbital septum? (2)
A
prevents fat from falling down into lid margins prevents infections moving into orbit
7
Q
is the lacrimal sac protected by the orbital septum?
A
no, orbital septum is behind the lacrimal sac
8
Q
what is the periorbita?
A
loosely covers the orbital bones, continous with orbital septum and fuses with dura of the optic nerve
9
Q
where does the superior palpebral levator muscle originate from?
A
lesser wing of the sphenoid main retractor of upper lid continuous with the levator aponeurosis
10
Q
what is whitnall’s ligament?
A
fulcrum for the palpebral levator muscle attaches to zygomatic
11
Q
what is the muscle of muller?
A
sympathetic muscle in eyelids minor retractor of upper lid
12
Q
which cranial nerve opens the eye? Which closes it?
A
CN III open CN VII closes
13
Q
where are goblet cells located?
A
epithelial layer of the conj. most numerous in the infernonasal fornix
14
Q
function of glands of zeis?
A
lubrication of eyelashes
15
Q
function of glands of moll?
A
modified sweat glands in eyelid
16
Q
function of the glands of krause?
A
accessory lacrimal glands=maintenance tears located mostly in the fornices (Krause=crease)
17
Q
function of the glands of wolfring?
A
accessory lacrimal glands =maintenance tears more prevalent than krause mostly located on tarsal conj.
18
Q
what are the holocrene glands of the eyelid?
A
meibomian zeis (cell ruptures releasing contents)
19
Q
What are the apocrine glands of the eyelid?
A
moll goblet secretions bud off of cell plasma
20
Q
what are the merocrine glands of the eyelid?
A
wolfring krause cell products are emptied into a duct by exocytosis
21
Q
which nerves supply the sensory portion of the eyelids?
A
CN V V1 (ophthalmic)=superior lid V2 (maxillary)=lower lid
22
Q
what supplies blood to the deep layers of the eyelids?
A
internal carotid feeds into the palpebral arcades superficial supply from external carotid
23
Q
where do the conjunctival lymph nodes drain into?
A
lateral=parotid (preauricular) medial=submandibular
24
Q
what are the muscles of the eyebrow? (3)
A
frontalis= surprise/attention corrugator= concentration/sorrow procerus=menace/aggression all innervated by CN VII
25
where are the only lymph glands of the orbit located?
lacrimal gland
26
which nerve innervates the lacrimal gland and causes lacrimation?
CN VII parasympathetic
27
what is dacryoadenitis?
inflammation/infection of the lacrimal gland
28
which muscle controls the canaliculi?
muscle of horner assists in tear drainage
29
what is dacryocystitis?
infection of the lacrimal sac
30
where is the lacrimal sac located?
in a fossa formed by the lacrimal bone and the maxillary bones
31
where is the lacrimal gland located?
in a fossa of the frontal bone
32
what is the valve of hasner?
located at the end of the nasolacrimal duct prevents backflow
33
which EOMs originate in the common tendinous ring?
all rectus muscles and superior oblique
34
what is the origin of the superior oblique?
lesser wing of the sphenoid bone and the CTR physiologic origin=trochlea
35
where does the inferior oblique originate?
ANTERIOR at the maxillary bone
36
what does the superior lateral branch of the ophthalmic artery supply?
SR LR SO
37
what does the inferior medial branch of the ophthalmic artery supply?
MR IR IO
38
where is the pituitary gland located?
sella turcica of the sphenoid bone
39
where does CN V2 enter the orbit?
foramen rotundum
40
which bone contains the optic canal (optic nerve and ophthalmic artery)?
lesser wing of the sphenoid
41
what passes through the common tendinous ring and the superior orbital fissure? (3)
*NOA* Nasociliary nerve (V1) Oculomotor nerve Abducens nerve
42
what passes through the superior orbital fissure and ABOVE the common tendinous ring? (4)
superior ophthalmic vein frontal verve lacrimal nerve trochlear nerve "SOV FLighT"
43
what passes through the inferior orbital fissure and passes under the common tendinous ring? (1)
inferior ophthalmic artery
44
which bones make up the roof of the orbit? (2)
*FRONT-LESS* frontal (majority) lesser wing of the sphenoid
45
what bones make up the floor of the orbit? (3)
*My Pal gets his Z's on the FLOOR" maxillary (majority) palatine zygomatic
46
which bones make up the medial wall of the orbit? (4)
*ELMS* maxilla ethmoid lacrimal body of the sphenoid
47
which bones make up the lateral wall of the orbit? (2)
*Great Z* greater wing of the sphenoid zygomatic
48
what supplies the blood to the IR and SO EOMs?
infraorbital branch of the maxillary artery (branch of external carotid) (also lacrimal sac and lower lid)
49
what supplies blood to the inner 2/3rd of the retina?
central retinal artery (branch of ophthalmic artery)
50
what supplies blood to the LR, SR, SO EOMs?
superior branch of the ophthalmic artery (also levator)
51
what supplies blood to the MR, IR, IO EOMs?
inferior medial branch of the ophthalmic artery
52
what supplies blood to the optic disc?
circle of zinn (from short posterior ciliary arteries->ophthalmic artery)
53
what supplies blood to the major circle of the iris? (2)
long posterior ciliary arteries (from ophthalmic artery) anterior ciliary arteries
54
what feeds into the cavernous sinus?
superior and inferior ophthalmic veins middle & inferior cerebral vein
55
what does the cavernous sinus drain into?
internal jugular vein
56
what passes through the cavernous sinus? (6)
CN III CN IV CN I CN VI CN V2 internal carotid artery "3,4,6, V1, V2... V3 and 7 do not go through"
57
what is the average length of an emmetropic eye?
24mm
58
what is the thickness of the cornea?
.55mm in the center .67mm at periphery
59
what is the greatest refractive surface of the eye?
tear/air interface greatest change in index of refraction
60
what are the layers of the cornea? (6)
epithelium basement membrane bowman's layer stroma descemet's membrane endothelium
61
what would happen if you performed tonometry off of the corneal center?
abnormally high readings
62
4 layers of the corneal epihelium?
surface layer wing cells basal layer stem cells
63
where do corneal stem cells originate from?
palisades of vogt around the limbus
64
what is bowmans layer?
type 1 collagen does not regenerate NOT a basement membrane
65
what is the only mitotic layer in the cornea?
basal layer
66
what makes up the corneal stroma? (3)
keratoctyes collagen fibrils (type 1) ground substance (GAGs)
67
what is the glycocalyx?
sugar layer makes surface bind well with mucin layer of tears
68
what is the predominate GAG within the cornea?
keratin sulfate
69
what is descemet's membrane?
type 4 collagen produced by endothelium can regenerate
70
how many cells thick is bowmans layer?
zero! it is acellular
71
what is the function of corneal endothelium?
NA+/K+ pumps maintain hydration and transparency do not replicate
72
which layer of the corneal stroma is more likely to have edema?
posterior
73
what happens when corneal endothelial cells die?
other cells change shape (pleomorphism) or size (polymegathism) to compensate
74
what is the main source of oxygen for the cornea?
tear film when the eye is open conjunctival blood vessels when the eye is closed
75
what innervates the cornea?
CNV1 only anterior stroma, bowmans and epithelium have nerves enters mid-stroma
76
what are the two layers of the conjunctiva?
stratified non-keratinized epithelial layer submucosa (lymphoid and fibrous layers)
77
what is continuous with descemet's membrane?
schwalbes line
78
what are the 3 parts of the lens?
capsule epithelium cortex
79
what are the two methods for aqueous outflow? which is pressure independent?
corneoscleral: pressure dependent 80% uveoscleral: pressure independent 20%
80
what is the function of the plica semilunaris?
provides slack for the movement of conjunctiva
81
where do the lens zonules attach to the lens?
lens capsule
82
where is the germinal zone of the lens?
anterior to the lens equator
83
what is the index of refraction of the lens?
nucleus=1.41 anterior=1.38
84
what produces the lens zonules?
non-pigmented ciliary epithelium in the pars plana and pars plicata
85
what is the thickest part of the sclera?
1mm at posterior pole
86
what is the function of alpha crystallins in the lens?
molecular chaperones, keep other crystallins separated by correct distance keeps lens clear
87
what is the thinnest part of the sclera?
.3mm under the recti tendon insertions
88
what are the layers of the sclera? (4)
episclera sclera lamina fusca tenon's capsule
89
what is the difference between sclera and episclera?
episclera is LOOSE CT and HIGHLY vascular sclera is DENSE CT and AVASCULAR
90
which areas of the sclera contain elastin? (2)
scleral spur lamina cribrosa
91
what are the 2 parts of the trabecular meshwork?
uveoscleral (inner) corneoscleral (outer)
92
where is the iris thickest?
collarette thinnest at iris root
93
what are the two parts of the iris?
ciliary zone pupillary zone divided by the collarette
94
what are the layers of the iris? (4)
anterior border layer stroma anterior epithelium/dilator posterior pigmented epithelium
95
how is iris color determined?
the amount of melanin inside of the melanocytes NOT # of melanocytes
96
in which layer of the iris is the sphincter muscle located?
stroma
97
which layer of the iris gives it its color?
anterior border layer
98
in which layer of the iris is the dilator muscle located?
anterior epithelium/dilator muscle layer
99
what forms the blood-aqueous barrier? (3)
iris vessels ciliary body endothelium of schlemms
100
what is the canal of hanover?
area filled with aqueous between the anterior and posterior lens zonules
101
what is the canal of petit?
the retrolental space between the zonules and the vitreous
102
what are the valleys of kuhnt?
regions between the ciliary processes in pars plicata
103
what is the pars plicata?
anterior portion of ciliary body produces aqueous
104
where is the aqueous humor produced?
in the non-pigmented ciliary body epithelium in the pars plicata
105
what is the flow of aqueous humor? (5)
pars plicata-> posterior chamber-> pupil -> anterior chamber-> trabecular meshwork
106
where is the major circle of the iris found?
in the ciliary body
107
where do the lens zonules originate in the ciliary body?
pars plana
108
how is aqueous humor formed?
plasma that escapes the blood stream in the fenestrated capillaries of the major circle of the iris
109
where is the choroid the thinnest?
ora serrata
110
in which layer of the ciliary body is the major arterial circle of the iris found?
stroma
111
what innervates the choroid?
sympathetic nervous system causes vasoconstriction
112
whihc layer of the choroid contain the long posterior ciliary nerves?
suprachoroid lamina
113
what are the layers of the choroid? (4)
suprachoroid lamina stroma choriocapillaris bruch's membrane
114
what are the two vessel layers in the choroidal stroma?
Hallers (Huge) Sattler (small)
115
which layers of the choroid are vascular?
stroma choriocapilaris
116
where are fenestrated capillaries found in the eye? (2)
choriocapillaris major arterial circle of the iris
117
which layer of the choroid contains vortex veins?
stroma specifically hallers layer
118
what is the function of bruch's membrane? (2)
passage of nutrients from choriocapillaris to retina waste products from inner retina pass through to choriocapillaris
119
which layer of bruchs membrane can have angiod streaks?
elastic layer
120
where are drusen located?
between the inner collagenous layers of bruch's and the BM of the RPE
121
what supplies blood to the choroid?
long & short posterior ciliary arteries
122
what is the patellar fossa?
depression in the vitreous where the lens sits
123
what is the type of collagen found in the vitreous?
type II
124
what makes up the vitreous?
water (98%) type II collagen hyaluronic acid (GAG)
125
what are the attachment sites of the vitreous from strongest to weakest? (5)
vitreous base posterior lens optic disc macula retinal vessels
126
where is the vitreous base attached?
ora serrata
127
what is the ligament of weiger?
the attachment between the vitreous and the posterior lens and zonules
128
what is cloquet's canal?
former site of the hyaloid artery
129
from what embryonic tissue is neural retina derived?
neural ectoderm
130
what is a epicapsular star?
hyaloid remnant on anterior lens capsule
131
where does lipofuscin accumulate?
inside of RPE cells
132
what is a mittendorfs dot?
hyaloid remnant on posterior lens capsule
133
what does the myoid portion of the photoreceptor do?
Makes protein
134
which layer of the retina stores vitamin A?
RPE
135
what does the elipsoid region of the photoreceptor do?
Energy lots of mitochondria
136
where is rod density the greatest?
5mm around the fovea rod ring
137
what is located in the inner segment of the photoreceptor? (3)
myoid (makes protein) Ellipsoid (has mitochondria) cilium (connects to outer seg)
138
what is located in the outer segment of photoreceptors?
discs
139
how many discs are in a rod? how many in a cone?
600-100 per rod 1000-1200 per cone
140
which photoreceptor has a spherule?
rods
141
which photoreceptor has a pedicle?
cones
142
which photopigment is found in rods?
rhodopsin (507nm)
143
which cone photopigment absorbs blue light?
cyanolabe (440nm)
144
which cone photopigment absorbs green light?
chlorolabe (535nm)
145
which cone photopigment absorbs red light?
eryhtrolabe (565nm)
146
what synapses with rod spherules?
1 to 4 rod bipolar cell dendrites horizontal cell dendrites
147
which layer of the retina receives blood supply from both the choroid and the retina?
outer plexiform layer
148
where is the space formed during retinoschisis?
outer plexiform layer
149
which layer are hard exudates found in?
outer plexiform layer
150
what is the function of bipolar cells?
carry information directly from rods/cones to ganglion cells
151
what is the function of horizontal cells?
lateral inhibition
152
what is the function of interplexiform cells?
carry signals between OPL and IPL
153
what is the function of amacrine cells?
carry information laterally between bipolar, interplexiform, ganglion and other amacrine cells
154
what is the function of muller cells?
most common glial cell in the retina structural and nutritional support
155
which retinal cells provide inhibitory signals?
amacrine and horizontal
156
where do the ganglion cells of the retina synapse?
LGN
157
what is the most common type of ganglion cell?
midget ganglion (p1) a type of parvocellular cell with only one dendrite that synapses with one foveal bipolar cell
158
what is affected first in glaucoma, M-cells or P-cells?
M-cells
159
which ganglion cells are responsible for fine vision?
mideget ganglion cells (p1) because they only carry information from a single foveal cone
160
where are cotton wool spots located?
NFL
161
where are splinter/drance/flame hemorrhages located?
NFL
162
where are dot and blot hemorrhages located?
inner nuclear layer
163
____ million photoreceptors-> ____ million bipolar cells-> ____ million ganglion cells
128 million photoreceptors-> 35 million bipolar cells-> 1.5 million ganglion cells
164
where is excess glucose stored in the retina?
muller cells
165
in which layers of the retina are muller cells found?
ELM to ILM
166
what % of the population has a cilioretinal artery?
15-20%
167
how large is the macula?
5.5mm
168
which retinal layers are found in the foveola? (6)
RPE photoreceptor ELM ONL henle's fiber layer ILM
169
what is Henle's fiber layer?
layer in the fovea that contains axons of photoreceptors NO bipolar cells or ganglion cells are located in the fovea
170
what is the thickest portion of the retina?
parafovea
171
in a CN XII lesion, which way will the tongue deviate?
towards the lesion
172
in a CN X palsy, which way will the uvula deviate?
away from the lesion
173
what is the purpose of the pretectal nucleus?
pupil innervation
174
what connect CN III to CN IV, VI and VIII?
medial longitudinal fasiculus
175
what is the purpose of the superior colliculus? (2)
reflex eye movements saccades
176
which part of CN III projects to a contralateral EOM?
superior rectus
177
what are the three destinations for CN II fibers?
LGN Pretectal nucleus Superior colliculus
178
what is innervated by the superior division of CN III? (3)
superior rectus superior levator mullers muscle
179
what is innervated by the inferior division of CN III? (4)
medial rectus inferior rectus inferior oblique pupil
180
what is indicated by a CNIII palsy that involves the pupil?
since pupillary fibers are on the outside of CN III, its is likely and posterior communicating artery aneurysm
181
what is indicated by a CNIII palsy that spares the pupil?
since pupil fibers on on the outside, its is likely microvascular think diabetes or hypertension
182
which cranial nerve leaves from the dorsal side?
CN IV
183
which way would a patient with a right CN IV palsy tip their head?
same side as the lesion (but opposite side from the affected EOM) right head tilt
184
what do the long posterior ciliary nerves (division of V1) innervate? (4)
cornea (s) iris (s) ciliary muscle (s) dilator muscle (M)
185
what do the short posterior ciliary nerves (division of V1) innervate? (3)
cornea (s) iris (s) ciliary muscle (s)
186
branches of CN V1?
nasociliary frontal lacrimal
187
which division of CN V supplies the eyelids?
upper=V1 lower=V2
188
what is the sensory innervation to the inferior medial eyelid?
nasociliary branch of V1
189
which type of aneurysm should you suspect with a CN VI palsy?
internal carotid
190
which cranial nerve is responsible for taste in the posterior 2/3 of the tongue?
VII
191
which cranial nerve stimulates lacrimation?
VII V is sensory
192
which CN innervates the orbicularis oculi?
zygomatic branch of CN VII
193
what is the ocular difference between bells palsy and a stroke?
a patient with a stroke can still voluntarily close their eyelids, a bells palsy patient cannot bells palsy can cause exposure keratopathy from lagopthalmos
194
what are the parasympathetic innervations of the eye?
CN III=iris sphincter and ciliary body (miosis and accommodation) CN VII=lacrimal gland (lacrimation)
195
where is the damage in a stroke? bells palsy?
stroke: supranuclear Bells palsy: lower motor neurons
196
why do patients with optic neuritis experience pain on eye movements?
because the optic nerve sheath is attached to the SR and MR muscles
197
what is the vidian nerve?
sympathetic innervation of the lacrimal gland makes you NOT cry
198
what is the internal limiting membrane of elsching?
the astrocytes that cover the optic disc
199
what is the border tissue of jacoby?
separation of the optic nerve fibers from the choroid
200
which parts of the eye can autoregular blood supply? (2)
optic nerve retina
201
what is the intermediary tissue of kuhnt?
ring of glial tissue that separates the optic nerve fibers from the retinal tissue
202
what is the border tissue of elsching?
scleral collagen fibers that surrounds the glial tissue of the optic nerve
203
where does myelination of the optic nerve begin?
posterior to the lamina cribrosa oligodendrocytes
204
what are the anterior knees of wilbrand?
inferior nasal fibers from contralateral eye loop back to opposite optic nerve
205
what are the anterior knees of wilbrand?
superior nasal fibers from contralateral eye loop back to opposite optic nerve
206
which layers of the LGN are magno? parvo?
1, 2=magno 3,4,5,6=parvo
207
what % of optic nerve fibers go to the LGN?
90%
208
which layers of the LGN are crossed? uncrossed?
crossed= 1(m) 4,6 (p) uncrossed= 2 (m) 3,5 (p)
209
the inferior optical radiations move through which part of the brain?
temporal lobe
210
where do superior fibers go in the LGN? inferior?
SMILe Superior: medial Inferior: lateral
211
the superior optical radiations move through which part of the brain?
parietal lobe
212
what separates the cuneus and lingual gyrii?
calcarine fissure
213
where do the superior retinal fibers terminate?
cuneus gyrus
214
where do the inferior retinal fibers terminate?
lingual gyrus
215
what is meyer's loop?
pathway taken by inferior optic radiations that go around the tip of the lateral ventricle before reaching the occipital lobe
216
where do the optic radiations synapse with the neurons of the striate cortex?
layer 4 of the primary visual cortex
217
which layer of the primary visual cortex sends signals to the superior colliculus?
layer 5
218
of the primary visual cortex sends feedback to the LGN?
layer 6
219
where does binocular visual processing first occur along the visual pathway?
primary visual cortex
220
what is the blood supply to the primary visual cortex? (2)
posterior cerebral artery middle cerebral artery
221
where is a lesion in a homonoymous VF defect?
post-chiasmal
222
what will cause a "pie in the sky" VF defect?
temporal lobe lesion PITS= parietal/inferior temporal/superior
223
what will cause a "pie on the floor" VF defect?
parietal lobe lesion PITS= parietal/inferior temporal/superior
224
what will cause a macular sparing homonymous hemiopsia?
a stroke to either posterior or middle cerebral artery
225
what causes macula only homonymous hemianopsia?
compressive lesion (tumor)
226
which muscle helps drain tears?
muscle of horner
227
how much does the superior levator muscle retract the eyelid?
15mm
228
how much does mullers muscle retract the eyelid?
1-3 mm
229
what muscle would be paralyzed in a large ptosis? small ptosis?
large: levator small: mullers
230
what type of tears are produced by the main lacrimal gland? (2)
reflex emotional
231
which forehead muscle will fatigue with ptosis?
frontalis
232
what is the tertiary action of the superior/inferior rectus muscles?
adduction
233
what is the tertiary action of the oblique muscles?
abduction
234
where does CN V3 enter the orbit?
Foramen Ovale
235
what is the thinnest orbital bone? weakest?
thinnest: ethmoid weakest: maxillary
236
what causes vision loss in GCA?
loss of blood supply to the short posterior ciliary arteries NOT JUST TEMPORAL ARTERY DISEASE
237
what is a cavernous sinus fistula?
abnormal connection between arterial and venous blood supply in cavernous sinus painful red eye, orbital bruit, proptosis
