Anatomy Flashcards
1
Q
Telecanthus
A
An abnormal large distance between the medical acanthi of the lids
2
Q
Poliosis
A
whitening of the eyelashes
3
Q
Madrosis
A
Eyelashes falling out
4
Q
Trichiasis
A
Turning inward of the lashes
5
Q
Pthiriasis Palpebrarum
A
An infection of the lashes caused by pthiriasis pubis
6
Q
Why is the skin layer of the eyelid unique
A
It is the thinnest in the body and contains no fat
7
Q
Which layer is below the skin layer of the eyelid
A
Subcutaneous areolar layer. Contains the elevator aponeurosis
8
Q
Orbicularis Layer
A
CN VII. Closes the eye.
9
Q
Orbital portion or orbicularis
A
Attaches to the orbital margins and extends outward. used in force closure
10
Q
Palpebral portion of orbicularis
A
Used for spontaneous and reflex blinking. Made up of muscle of riolan and muscles of horners
11
Q
Muscles of Riolan
A
Pars ciliaris. Most superficial orbicular oculi. Keeps lid margin tightly applied to the globe. May rotate the eyelash inward with eyelid closure.
12
Q
Gray line
A
Most anterior portion of the muscle of Riolan. Between the eyelashes and the meiobomian glands.
13
Q
Muscle of Horners
A
Pars lacrimalis. Encircle the canaliculi and help drain tears into the lacrimal sac.
14
Q
Submuscualar areolar layer
A
Between the orcicularis and the orbital septum. Contains the elevator aponeuris, palpebral portion of main lacrimal gland, and the peripheral and marginal arcades.
15
Q
orbital Septum
A
Dense irregular connective tissue that serves as a barrier to the orbit. Prevents fat from falling down and keeps infections out.
16
Q
Periorbita
A
covers the orbital bones. Projects anteriorly to become the orbital septum and posteriorly to fuse the dura of the ON head.
17
Q
Where does the orbital septum attach
A
Medially to the posterior lacrimal crest (i.e. behind the lacrimal sac)
18
Q
What inserts in the superior orbital septum
A
levator aponeurosis
19
Q
Posterior muscular system
A
mullers muscle and Levator.
20
Q
Superior palpebral levator orgin
A
lesser wing of the sphenoid
21
Q
How much does it retract the lid?
A
15 mm
22
Q
Whitnall’s ligament
A
Changes the direction of the Levator and allows it to perform its function.
23
Q
Levator aponeurosis
A
A fan of the elevator in the eyelid.
24
Q
Superior palpebral furrow
A
Formed by the elevator aponeurosis sending fibers through the tarsal plate to insert in skin.
25
Lateral horn of elevator aponeurosis
Travels across lacrimal gland and attaches to whitenall's ligament.
26
Medical horn of levator aponeurosis
Travels medical to medial palpebral ligament
27
Inferior palpebral furrow
formed by indirect attachment of the IR into the skin of the lower eyelid.
28
Muscle of Muller
Innervated by alpha 2 of SNS. Originates from elevator and extends to the tarsal plate.
29
How much does muscle of muller widen eyelid
1-3 mm (minor)
30
Inferior tarsal msucle
original from fascial sheath of the IR and extends into the tarsal plate.
31
Normal interpalpebral distance in adults
10-12 mm
32
Tarsal Plate
Dense irregular CT that provides rigidity to the eyelids. Surrounds the meiobomian glands.
33
What do the tarsal plates become?
The medial and lateral palpebral ligaments.
34
Where does the medial palpebral ligament attach?
maxillary bone
35
Where does the lateral palpebral ligament attach
Whitnall's ligament (also where lateral horn of Levator aponeurosis)
36
Layers of palpebral conjunctiva
Epithelial and stroma layer
37
Epithelial layer of the palpebral conjunctiva
Extends into the fornices and bulbar conj. Contains the goblet cells that produce the mucin layer of the tears.
38
where are goblet cells most commonly found
infernasal fornix and on bulbar conj temporally
39
Layers of Stroma of the palpebral conj.
Made up of superficial lymphoid layer and deep fibrous layer
40
Superficial lymphoid layer of the palpebral conj
Very immunologically active. Has IGA, macrophages, mast cells, PMNs, eosinophils.
41
Deep fibrous layer of palpebral conj.
Connects the conjunctiva to to underlying structures. Contains the accessory lacrimal glands, nerves, blood vessels of the eyelids. Becomes continuous with tarsal plate.
42
How many meiobomian glands are there
25 on top and 20 on lower
43
What do meiobomian glands produce and what kind are they
The lipid layer of the ear film. Holocene (whole cell shed)
44
Glands of Zeiss. What kind?
Lubricate the eyelashes. Also help with lipid layer. Holocrine.
45
Glands of Moll
Empty contents into lashes, glands of zeiss, and lid margin. Also help with lipid layer. Apocrine.
46
Glands of Krause
Accessory lacrimal glands. Mesocrine. Located in fornices of the conjunctiva (krause in creases).
47
Glands of Wolfring
Accessory lacrimal glands. Mesocrine. Larger and less numbers. In Tarsal conjunctiva.
48
Holocrine glands
Meiobomian and Zeiss. Secrete entire cell.
49
Apocrine
Moll and Goblet. A portion of plasma membrane buds off.
50
Mesocrine
Accessory lacrimal glands. Secrete by exocytosis.
51
What branch of CN VII controls the lid
Zygomatic controls orbicularis oculi
52
Involuntary motor innervation of the lid
Muscle of Muller controlled by SNS
53
Sensory innervation of the lid
Upper eyelid innervated by frontal and lacrimal branches of V1. Lower eyelid innervated by infraorbital and zygomaticofacial branch of V2.
54
Which innervation supplies both upper and lower lid senstation
infratrochlear branch of nasociliary from V1.
55
Branches of V1
Nasociliary, Frontal, Lacrimal
56
Nasociliary Branches
infratrochlear, anterior ethmoid, posterior ethmoid, long ciliary, short ciliary.
57
Branches of frontal nerve
Supratrochlear and Supraorbital
58
Branches of V2
Infraorbital and zygomaticofacial.
59
What layer are the palpebral arcades located in
Submuscular areolar layer
60
What forms the palpebral arcades
Medial palpebral artery (from ophthalmic artery or dorsal nasal artery) and lateral palpebral artery (from the lacrimal artery)
61
Marginal palpebral arcades
near the eyelid margin
62
Peripheral palpebral arcades
Supply the fornices and the posterior conjunctiva. Connect with anterior ciliary arteries which supplies the anterior conj.
63
What do Anterior ciliary arteries provide
Provides circulation to the bulbar conj. and the CB. Why a patient with uveitis can have circumlibal injection.
64
What external artery branch provides the lids
The facial artery
65
Where do lateral lymphatics drain
Parotid (pre auricular) lymph nodes
66
Where do medial lymphatics drain
submanidubular lymph nodes
67
What is the only type of bacterial conjunctivitis that presents with parotid lymphadenopathy swelling?
Gonococcal conjunctivitis
68
What commonly results in pre auricular lymphadenopathy
viral infections. (viral conjunctivitis, chlamydia conjunctiviies, and dacryoadentitis)
69
Frontalis
The main elevator of the brows. Originates high on the scalp and inserts near the Superior orbital rim
70
Corrugator
Concentration or sorrow. Medial depressor of the eyelids. Originates at frontal bone and inserts in skin above medial eyebrows.
71
Procerus
Agression. Pull the skin between the eyebrows downward. Originates at nasal bone and inserts on the frontal.
72
What divides the lacrimal gland?
The superior palpebral elevator tendon
73
How does the lacrimal gland receive parasympathetic innervation
From the lacrimal nerve of the pterygopalantine ganglion of CN VII.
74
How does the lacrimal gland receive sympathetic innervation
SNS follows the lacrimal artery to innervate the gland.
75
Acute dacryoadentitis
inflammation of the lacrimal gland. S shaped.
76
What is responsible for keeping the lacrimal puncta open
Lacrimal papilla
77
Cannaliculi
10mm long. Connects the punch to the lacrimal sac. Runs 2mm vertical and then 8mm medially to join the common canaliculus that joins into the lacrimal sac.
78
What does the muscle of Horners do?
During eyelid closure it contracts and assists with tear draining.
79
What bones form the lacrimal fossa
Lacrimal bone and maxillary bone.
80
How long is the lacrimal sac
10-12 mm
81
What tendon straddles the lacrimal sac
Medal palpebral ligament (from the tarsal plates)
82
Darcyocystitis
Infection of the lacrimal sac.
83
What sinus does the nasolacrimal duct lay adjacent to
maxillary sinus.
84
How long is the nasolacrimal duct?
15 mm
85
Where does the nasolacrimal duct terminate
inferior meatus
86
Valve of hasner
At the end of the nasolacrimal duct. Stops back flow
87
Intraconal Adipose Tissue
Within the cone. Separates ON from the EOMs
88
Extraconal adipose tissue
outside of the cone. Between the EOMs and wall of orbit.
89
The Sheath of the _____ and _____ are connected
SR and elevator. Allow lids to go up with upward movement.
90
Spiral of Tillaux
The insertion of the rectus muscles. Medial is closest, then inferior, then lateral, then superior.
91
MR insertion
5.5 mm
92
IR inserteion
6.5 mm
93
LR insertion
6.9 mm
94
SR insertion
7.7 mm
95
Where do all recti muscle originate
CTR
96
SO origin
Lesser wing of sphenoid and CTR.
97
Physiological origin of SO
trochlea
98
IO origin
Only muscle to originate anteriorly. Originates from the maxillary bone.
99
Muscular artery branches
Superior lateral and inferior medial
100
Superior lateral artery supplies...
SR, SO, LR.
101
Inferior medal artery supplies
IR, IO, MR.
102
Superior division of the CN III supplies what...
SR.
103
Inferior division of the CN III supplies what...
MR, IR, IO.
104
What creates the orbital septusm
Orbital fascia
105
What is in lesser wing
Optic canal, elevator starts, So starts
106
Great wing forms the
Lateral wall
107
Foramen within greater wing
Formen rotundum (v2), formane ovale (v3), formane spinosum (middle meningeal artery)
108
Where is the SOF
between the greater and lesser wing.
109
Annulus of Zinn
Common tendinous ring. Orgin of the Rectus muscles
110
What goes through the CTR and SOF
Nasociliarty of V1 (along with sympathetic root), oculomotor nerve, Abducens nerve.
111
What goes through SOF but above the CTR
Superior ophthalmic vein, frontal nerve, lacrimal nerve, trochlear nerve. SOV, FLighT.
112
What goes through IOF and below CTR
inferior ophthalmic vein and occasionally central retinal vein if it hasn't joined ophthalmic vein)
113
what goes through carotid canal
Internal carotid artery and Sympathetic plexus
114
what goes through Supraorbital formaen
supraorbital n. (V1) and vessels
115
what goes through Infraorbital formaen
infraorbital n. (v2) and vessels
116
what goes through sylomastoid formen
facial nerve
117
mnemonic for bones that make up the orbit
Many Friendly Zebras Enjoy Lazy Summer Picknicks
118
What makes up the roof of the orbit
Front-less. The lacrimal gland is in a fossa in the frontal bone
119
What makes up the floor of the orbit
My Pal gets His Z's on the floor. Maxillary, palatine, Zygomatic.
120
what makes up the medial wall
SMEL. Body of sphenoid, Maxillary, ethmoid, lacrimal.
121
Lamina Papyracea
Orbital portion of the ethmoid. Very thin. Infectious of sinus can spread
122
Lateral wall
Great Z. Great wing of sphenoid and zygomatic.
123
Which wall does not have sphenoid
inferior
124
cavernous hemiagnomas
most common benign orbital tumors in adults
125
capillary hemangionomas
most common being orbital tumors in kids
126
Important branches of the external carotid artery
Facial artery, superficial temporal artery, and maxillary artery.
127
Angular artery
Terminal branch of the facial artery that supplies medical canthus with the dorsal nasal artery (from ophthalmic artery)
128
Maxillary artery
A terminal branch of external carotid artery. Gives of infraorbital artery that supplies IR and IO and exits orbit and supplies the lower eye lid and lacrimal sac before joining with the angular artery and the dorsal nasal artery
129
Anastomose of the lacrimal sac
infraorbital (ECA), angular (ECA), and dorsal nasal (ICA). DAI.
130
Superficial temporal artery
Branches Ant temporal, zygomatic, transverse.
131
Which nerve travels closest to the ICA
CN VI
132
Where does the ophthalmic a. branch from
Internal carotid
133
Branches of the ophthalmic artery
CRA, Lacrimal A, Muscular, SPCA, LPCA, Supraorbital, Ethmoid. -->Supratrochlear and Dorsonasal.
134
Lacrimal artery branches
Travels along the lateral wall and supplies the lr and lacrimal gland. It terminates as the lateral palpebral artery for lacrimal arcades.
135
Muscular artery
Superior lateral: SO, SR, LR. Inferior Medial: IO, IR, MR
136
What lawyers are the CRA in
NFL and ONL/OPL
137
Anterior ciliary artery
formed by branches of the muscular arteries. Combines with LPCA to form MACI
138
Short Posterior Ciliary Artery
Forms the circle of Zinn to supply optic nerve, posterior choroid, and macula.
139
Long Posterior Ciliary Artery
Travel between sclera and choroid. Provide the anterior choroid before forming MACI.
140
What makes up MACI
Anterior ciliary arteries (from muscular branches) and LPCA.
141
Supraorbital artery
Provides SR, SO, elevator before going through Supraorbital notch to supply the scalp.
142
Ethmoid artery
Branches supply the sphenoid, frontal, and ethmoid sinuses.
143
Supratrochlear artery
Terminal branch of ICA. Supplies the forehead, scalp, and muscles of forehead
144
Dorsal nasal artery
Supplies lacrimal sac and then joins angular (facial-ECA)
145
Medial palpebral artery
branch of dorsal nasal that form palpebral arcades.
146
What causes ocular ischemic syndrome?
Occlusion of ICA or ophthalmic artery.
147
Central Retinal Vein
Drains blood from the inner 6 layers of the retina that are supplied by the CRA. Exits through the optic nerve and then enters the cavernous sinus, either directly or joining with superior ophthalmic veins first.
148
Anterior Ciliary Veins
Drain the anterior structures. Drain into the superior and inferior ophthalmic veins.
149
Vortex veins
Drains blood from the choroid. Drain into the superior and inferior ophthalmic veins.
150
Superior Ophthalmic Veins
Drains the majority of the eye (muscular=MR and SR) Formed by angular artery (formed by supraorbital and facial). Exits through the SOF and then joins the cavernous sinus.
151
Inferior ophthalmic veins
Drains muscular (MR, LR, IO, IR). Divides into superior and inferior branch
152
Superior branch of inferior ophthalmic vein
Exits through SOF and then drains directly to cavernous sinus or joins with SOV
153
Inferior branch of inferior ophthalmic vein
Exits through IOF and then drains into ptyergopoid plexus to communicate with facial veins
154
Supraorbital vein
Combines with the facial v. to form angular v. -->SOV
155
Angular vein
Becomes the anterior facial vein. Gets blood from pterygoid venous plexus and superior and inferior palpebral veins. Joins with posterior facial vein to form the common facial vein. Common facial vein drains into internal jugular vin.
156
Infraorbital vein
drains the lower face and then drains into the pterygoid plexus
157
Ptergoid venous plexus
The anterior facial vein (from angular), Inferior branch of IOV, and infraorbital all drain into it. Communicates with cavernous sinus with orbital veins and emissary veins of the cranium.
158
What does the venous plexus form?
The maxillary vein
159
Superficial temporal vein
Joins the maxillary vein within the parotid gland to form the posterior facial vein (combines with anterior facial to form form common facial).
160
Middle temporal vein
Drains into the superficial temporal vein. Receives blood from the orbital vein that originates from lateral palpebral venous branches.
161
Posterior Facial vein
Formed by superficial temporal vein and maxillary vein. Divides into an anterior and posterior branch
162
Anterior branch of posterior facial vein
Joins with anterior facial vein to form common facial v. then drains into internal jugular vein.
163
Posterior branch of posterior facial vein
Joins with the posterior auricle vein to form the external jugular vein
164
Occipital vein
Can drain directly to the internal jugular vein or join the posterior auricle to drain into the external jugular vein
165
External jugular vein
Formed by union of posterior facial vein (retromandibular vein) and the posterior auricular vein and drains blood from the superficial face.
166
Internal jugular vein
Continuation of the sigmoid sinus and drains the common facial, occipital, lingual, and superior and medical thyroid veins.
167
What travels through the Cavernous Sinus
V1, V2, III, IV, VI, ICA, post ganglionic sympathetic fibers that travel around ICA, and parasympathetic fibers around CN III
168
What does not go through the cancerous sinus
V3, CN VII (and parasympathetic fibers that travel with CN VIII)
169
Tolosa Hunt Syndrome
Inflammation of SOF or Cavernous sinus. Has painful external othamolpegia and diplopia.
170
Carotid Cavernous Fistula
Abnormal communication between the arterial and venous blood supplies in the cavernous sinus. Associated with painful red eye, ocular bruit, and pulsatile proptosis.
171
Superior Petrosal Sinus
Drains the inferior cerebral and some cerebellar veins. Communicates with cavernous sinus and transverse sinus.
172
Inferior Petrosal sinus
From the posterior inferior cavernous sinus. Exits through the jugular foramen and drains into internal jugular vein
173
Superior Saggital sinus
Located in the falx cerebra. Drains into the right transverse sinus.
174
Inferior saggital sinus
in the inferior fall cerebri. Forms the straight sinus.
175
Straight sinus
Originates at the junction of the falx cerebra and tentorium. Drains into the left transverse sinus.
176
Occipital sinus
Drains into the left transverse sinus.
177
Transverse sinus
Form the sigmoid sinuses.
178
Sigmoid sinus
Exits and becomes the internal jugular vein.
179
Confluence of the Sinuses
Metting point of Superior sagittal, straight, occipital, and transverse sinus. Located on the internal occipital protuberance. SS TOS.
180
Average axial length
24 mm
181
Why is the cornea able to refract so well?
The large difference in n values between the air and tears.
182
Where is the cornea thicker?
The periphery.
183
Central radius of curvature for the front of the cornea
7.8 mm
184
Central radius of curvature for the back of the cornea
6.5 mm (steeper)
185
Diameter of anterior
Horizontal=11.7 Vertical=10.6
186
Diameter of posterior
11.7 horizontal and vertical
187
What has type 4 collagen in the cornea?
BM and descemts.
188
What forms the epithelium
surface ectoderm.
189
Surface layer of the corneal epithelium
2 layers of non-keratizinzed squamous cells. Plasma membrane secretes a glycocalyx and contains micropillae and microvillae.
190
What is the only layer in the cornea to have ZO
epithelium surface layer
191
Wing cells
2-3 layers going by desmosomes
192
Basal layer of epithelium
Only mitotic layer in corneal epithelium. Made up of 1 layer of columnar cells. Basal layer secretes basement membrane. Attaches to basal layer by hemidesmosomes.
193
Increased chances of RCE
1. poor hemidesomes attachment 2. EMD 3. age related thickening of cornea
194
Palisades of Vogt
Where all stem cells of epithelium are. 1 mm band at the layer of the basal.
195
Is bowman's layer a BM?
NO
196
What type of collagen is Bowman's made up of
Type 1. Bones and sclera too.
197
What makes bowman's layer
Prenatally by anterior stroma.
198
What function may bowman play
Maintaining the curvature of the cornea
199
Band Keratopathy
Calcium deposits within bowman's layer (swiss cheese)
200
Crocodile Shagreen
Gray-white polygonal stroll opacities that may involve bowman's layer
201
Keratocytes of the stroma
Fibroblasts the produce collagen fibrils and the extracellular matrix
202
Collagen fibrils of the stroma
Uniformly spaced lamellae.
203
The anterior 1/3 of the storm has a ______ incidence of cross linking
Greater
204
The posterior 2/3 of the storma is _______ organized and has less uniformly lamellae and ____ cross linking
more, more
205
The less cross linking with the posterior stroma results in
higher incidence of corneal edema
206
What is the GAG in the cornea?
Keratin Sulfate
207
What produces Decesments?
The corneal endothelium.
208
What type of collagen is descements?
Type 4
209
Schwalbe's line
The ending of descents at the limbus
210
Hydrops
Occurs in keratoconus as a results of rupture of descements
211
Haab's striae
Folds in descements with congenital glaucoma
212
Hassal-Henle bodies
small ares of thickened descent's in the corneal periphery. Increase in number with age and have no visual significance.
213
Endothelium of the cornea
Squamous cells with NA/K ATP pumps that maintain corneal hydration and transparency.
214
Where does cornea obtain nutrients?
Aqueous humor, Limbal conj and episcleral capillary networks, and palpebral conj. vessels.
215
Main source of O2 in the open eye
tear film
216
Main source of O2 in the closed eye
Palpebral conjunctival blood vessels.
217
What is corneal innervation responsible for
wound healing and pain sensation
218
Where do LPCN's enter cornea?
The midstroma. After traveling 2-4 mm inside stroma, the corneal nerves lose their myelin sheath as they penetrate bowman and are now nocireceptors.
219
Where are there no nerves in the cornea
Endo, descemets, posterior stroma.
220
Stratified non-keratizined layer of conjunctiva?
Made of cuboidal/columnar cells in palpebral and squamous in the bulbar conj. Superficial cells have melamine granules, microvilli, and goblet cells.
221
Submucosa of the Conj.
Outer lymphoid layer has IGA, etc.. Deep fibrous layer has collagen fibrils, fibroblasts, blood, vessels, accessory lacrimal glands.
222
Palpebral marginal conj.
Lines the eyelid margins. Submucosa is thin with only a deep fibrous layer.
223
Palpebral tarsal conj.
Lines the tarsal plate. Submucosa is thicker. Strongly attached to tarsal plate.
224
Forniceal conj.
Lines the fornices. The EOM fascia attach to the forniceal conjunctiva that allow conj to move with eyes.
225
Bulbar conj
Submucosa is losely attached under tenon's capsule until 3 mm from the cornea where it fuses with tenon's episclera, and sclera.
226
What stops at limbus
Bowman's and descents (continues as Schwalbe's)
227
What begins at the limbus
conj stroma, episclera, and tenon's capsule.
228
Plica Semilunaris
Made of stratified squamous bulbar conj that folds at the medial cants. Allows eye to move and floor of lacrimal lake.
229
Caruncle
Conj and skin hybrid with sebaceous glands, sweat glands, and goblet cells. Function is unknown.
230
What drains the bulbar and palpebral conj
anterior ciliary veins
231
What supplies blood to palpebral conj?
Palpebral arcades
232
What supplies blood to bulbar conj?
Posterior supplies to peripheral palpebral arcades and anterior bulbar by anterior ciliary arteries.
233
Anterior lens radius of curvature
8-14
234
Posterior lens radius of curvature
5-8
235
Lens capsule
Transparent basement membrane that surrounds the entire lens and is secreted by the anterior lens epithelium. Zones insert here.
236
What collagen is lens capsule made of
Type 4
237
Lens epithelium
Single layer of cuboidal cells adjacent to the lens capsule. Joined to together by macular occludences and gap junctions
238
Pre-Equatorial region of the lens
Just anterior to the lens equator and known as the germinal zone. Contains mitotic epithelial cells that become secondary lens fibers.
239
Lens cortex
70% water and 30% protein (highest in body). Most lens proteins are water soluble.
240
Crystalline in the lens cortex
Have alpha, beta, and gamma. Alpha crystalline are in charge and help the others. When we loose them we get cataracts.
241
Index of refraction in the cortex
Gradient index highest in the nucleus.
242
Lens Zonules
BM of NPCE creates lens zonules. Has no true elastic fibers.
243
Primary lens zonules
Attach directly to the lens zone in the pre and post equatorial regions
244
Secondary lens zonules
Connect primary lens zonules to one another or the NPCE of the pars plana
245
Tension zonules
connect the primary lens zonules to the alleys between the ciliary processes of the pars plicate.
246
Where is the sclera thickest? how thick?
posterior pole at 1 mm
247
Where is the clear thinnest? how thin?
Under recti tendon insertions. 0.3 mm.
248
Where is the weakest area of the sclera
lamina cribosa
249
Is the sclera vascular?
NO. Considered avascular. Receives minimal blood supply from episcleral vessels, choroidal vessels, and branches of LPCAs.
250
Layers of the sclera
episclera, sclera proper, lamina fusca
251
Episclera
Loose CT layer that contains a capillary network for Anterior ciliary arteries. Will get injection with CB or iris inflammation.
252
What is on top of the episclera?
Tenon's capsule
253
Sclera Proper
Thick, dense, avascular CT. Irregular collagen bundles that provide strength but no transparency.
254
What is sclera proper a continuation of?
Corneal stroma
255
Episclera vs. sclera proper
Episclera is loose CT and highly vascular. Sclera proper is dense CT and is relatively avascular.
256
Lamina Fusca
The innermost layer of the sclera. Adjacent to choroid and continues elastic fibers and melanocytes.
257
Tenon's Capsule
Thin transparent layer that covers the episclera. Pierced by EOMs, vessels, etc.
258
Layers of the eye from anterior to posterior
conj epi, conj. stroma (submuconsa), Tenon's capsule, episclera, sclera proper, lamina fasca.
259
Anterior sclera foramen
Area occupied by the cornea
260
Posterior sclera formaen
Are occupied by the ON. Lamina cribosa.
261
Emissaria
Channels in the sclera for things to travel.
262
Middle emissaria
Vortex veins
263
Posterior emissaria
LPCAs, SPCA, LPCN, SPCN.
264
Anterior emissaria
Anything not stated in middle or posterior :)
265
Internal sclera Sulcus
Located in the eye and has the cornea sclera junction
266
Becker-Shafter Grade 4
Most posterior structure seen is CB
267
Becker-Shafter Grade 3
Most posterior structure seen is sclera
268
Becker-Shafter Grade 2
Most posterior structure seen is 1/2 to 1/3 TM
269
Becker-Shafter Grade 1
Most posterior structure seen is anterior aspect of TM or schwalbe's line
270
Becker shaffer grade 0
no structures seen
271
Van Herick grade 4
Anterior chamber is >1/2
272
Van Herick Grade 3
Anterior chamber is 1/2 to 1/4
273
Van Herick Grade 2
Anterior chamber is =1/4
274
Van Herick Grade 1
<1/4
275
Van Herick Grade 0
no structures visible
276
What attaches to the Scleral Spur
TM and longitudinal muscle fibers of the CB
277
Which layers of the sclera contain elastin
Lamina fuscha, lamina cribosa, and SS
278
Which part of the angle typically contains the most pigment
inferior
279
Uveoscleral meshwork
Innermost 1-5 layers of the TM. Large pores. Does not utilize Schlem's canal. Aqueous flows between the ciliary muscle fiber bundle, into the suprachoridal space, and then through the sclera or through the anterior ciliary veins, vortex veins, or other routes.
280
What to prostaglandins due
Decrease resistance in uveoscleral meshwork.
281
Corneoslceral Meshwork
Outer 8-15 layers. Has smaller pores. IOP must be greater than venous pressure.
282
Juxtacanalicular Tissue
AKA cribifirm layer. Located closest to schlem's canal. Much resistance.
283
Schelmm's Canal
A major site of aqueous humor filtration. Inner wall has vacuoles to collect for JXT. Has internal collector chambers to increase the SA.
284
Routes of schelemm's canal drainage
Short efferents->deep scleral venous plexus-->intrascleral venous plexus-->Episcleral venous plexus OR external collector channels (aqueous veins of Ascher)-->episcleral venous plexus.
285
Pupil location
Slighting IN.
286
Schwalbe's contraction furrows
At the pupillary margins. Represent variation in thickness of the Posterior pupillary iris.
287
Where is iris thickest?
collarette
288
Where is iris thinnest
Iris root
289
Collarette
Attachment for fetal pupillary membrane and has old fetal vasculature. Divides iris into pupillary and ciliary zones
290
Ciliary zone
Contains iris furrows that allows iris to bunch with dilation. Also has radial streaks which are white in color and represent collagen traveling with iris vessels.
291
Pupillary zone
Radial streaks are still present but are smaller.
292
Crypts of Fuchs
Span the collate into ciliary and pupillary zones
293
Anterior iris stromal leaf
Located in ciliary zone. Contains the ABL and a small portion of the iris stroma.
294
Posterior iris stromal leaf
Contains most of the iris stroma in the ciliary ABL and all of the iris stroma in the pupillary zone.
295
What determines iris color
amount of melanin not amount of melanocytes.
296
Iris crypts
columns in ABL that serve as passageway for aqueous humor.
297
Cells of the iris stroma
fibroblasts, melanocytes, lymphoctyes, macrophages, mast cells, clump cells.
298
What is the iris stroma continuous with?
Ciliary body stroma
299
Nerves of the iris stroma
LPCNs and SPCNs.
300
What carries sensory and sympathetic signals to iris stroma?
LPCNs and SPCNs
301
What carries parasympathetic signals to iris stroma
SPCNs.
302
What is the blood aqueous barrier
minor ACI, endo of scheme's canal, NPCE.
303
MACI
Major. Formed by LPCA and ACA. In the CB and extends to the iris root.
304
Minor ACI
Located in the iris stroma near pupillary margin and inferior to collarette. Formed by branches of MACI.
305
Radial veins
Veins of the iris and parallel the arteries. Drain into CB veins-->choroidal veins-->vortex-->super/inferior SOV.
306
Sphincter muscle
Present in the iris stroma.
307
What innervates the sphincter muscle
SPCN that travel with CN III
308
Anterior epithelium
Lies closest to iris stroma and becomes the pigmented ciliary epithelium. Contains pigment myoepithelial cells which which contain processes at basal surface that extend into iris stroma and attach to sphincter. This forms the dilator muscle
309
Dilator muscle
in the anterior epithelium layer. Extends from the iris root and stops at midpoint of sphincter.
310
Posterior Pigments Epithelium of Iris
Heavy pigmented single layer of columnar cells.
311
Pupillary ruff
PPE of iris extends around pupil.
312
What kind of transillumination defects will see with pigment dispersion syndrome
mid peripheral.
313
Iris cysts
Develop when there is separation between pigmented anterior layer and pigment posterior epithelium layer.
314
Where is the posterior chamber located
Between the iris and anterior vitreous.
315
Posterior chamber proper
bound by posterior iris epithelium, Cilliary processes, and the anterior zonules and surface of lens.
316
Canal of Hannover (aka circumlental space)
Between the anterior and posterior lens zonules. Hannover=pushover=always in the middle.
317
Canal of petit (aka retrolental space)
located between the most posterior lens zonules, anterior hyaloid membrane, and posterior portion of the CB.
318
Function of the CB
Aqueous humor production, Accommodation CN III.
319
How is the CB innervated by parasympathetic
CN III carry SPCN
320
Pars Plicata
Corona Ciliaris. Wide anterior portion that contains 70-80 Ciliary processes. The NPCE of the pars plicate is responsible for the production and secretion of aqueous humor into the posterior chamber
321
Par Plana
Orbiularis ciliaris. Flatter, more posterior.
322
Dentate processes
The teeth.
323
Oral bays
Part of CB. The ovals.
324
Enclosed oral bay
neighboring dentate processes joining together
325
Valley of Kuhnt
Heavily pigmented areas located between ciliary processes.
326
Where do the lens zonules come from
Mostly the NPCE of the pars plans.
327
Course of he lens zonule
Produced by the pars plans and then course forward to the valleys of kunt before inserting in the lens capsule.
328
Supraciliaris
The outermost layer of the ciliary body. Loosely attached to underlying sclera. It is a potential space. It is continuous with the suprachoriod at the ora errata. Blood vessels and nerves travel here.
329
Where does a ciliary body detachment occur
Fluid in Supraciliaris
330
Ciliary Muscle Longitudinal fibers
Outermost fibers that are most of the CM fibers. Originate at the SS and TM with legs extending into the chord as stellate shaped terminations (muscle stars)
331
Radial fibers
Also extend from SS.
332
Muller's annular Muscle
Smallest CM fibers. Most medical and located near MACI. originates from SS and has same effect as sphincter
333
Ciliary Stroma
Contains MACI.
334
Pigmented Ciliary Epithelium
The outer cuboidal epithelial layer layer that is attached to the ciliary stroma.
335
NPCE
Responsible for controlling aqueous
336
What supplies the CB with blood
MACI
337
What drains CB
Vortex veins
338
Innervation of the CB
1. CN III carry parasympathetic fibers from SPCNs. 2. SNS travels with SPCNs and LPCNs for arteries 3. Sensory nerves from V1 travel with LPCNs.
339
Where is the choroid thickest
posterior pole 0.2 mm
340
Where is choroid thinnest
Ora serrata 0.1 mm
341
Suprachoroid
potential space between the sclera and choroid vessels. Passage of LPCN and SPCN occurs here
342
Where do you see LPCN in BIO
3 and 9
343
Who does the suprachorid layer belong to (lamina fuscha)
Both choroid and sclera. If there is a seperation part will stick to choroid and part to sclera.
344
Choroidal stroma
Have choroidal blood vessels, nerves, and melanin. Innervated by the sympathetic NS which causes construction. The high density of bv and melanocytes gives the chance for nevus to occur.
345
Haller's Layer
Posterior layer of choir formed by SPCAs. Composed of large vessels that branch into smaller vessels in settler's layer.
346
Sattler's layer
More anterior and smaller vessels that branch to form a capillary bed.
347
Choriocapillaries
Composed of large fenestrated capillaries that are most concentrated in the macula. Nourishes the outer layers of the retina.
348
Pericytes
surround blood vessels and regulate flow.
349
Bruch's Membrane
Thin innermost layer of choroid. Represents the fusion of the RPE and Choriocapillaris.
350
Layers of bruch membrane
BM of choriocapillairis, Outer collagen layer, elastic layer, innercollegent layer, Bm of RPE.
351
Functions of bruch membrane
allow passage of nutrients from choroid to Retina, Waste products pass to choroid, phosolipids accumulate with age and cause drusen and stop transport.
352
What conditions have angoid streaks
PEPSI. Psuedoxanthoma elasticum, Ehlers-dahlos, Pagets, Sickle cells, Idiopathic
353
What conditions cause neovacsularization
CH BALA. Choroid rupture, hitso, Bests, Angoid, Lacquer, ARMD.
354
Innervation of the choroid
Sympathetic fibers cause vasoconstriction, CN VII parasympathetic from ptergyopalantine cause vasodilation, CN III parasympathetic have unknown function, CN V1 provides sensory information.
355
Patellar fossa
Anterior depression of the vitreous due to the lens
356
What type of collagen is the vitreous
Type II
357
Where do most of the changes in vitreous with age occur?
Central vitreous
358
Halocytes
The predominate cell type in the vitreous and are only found there. Synthesize HA and have phagocytic properties.
359
Hyaluronic acid
The gag in the vitreous.
360
Fibroblasts in the viterous
Predominately in the base and synthesize collagen.
361
Virtual attachment from strongest-->weakest
Vitreous base, posterior lens, optic disc, macula, BV.
362
Vitreous cortex
Outer region of the vitreous adjacent to the retina that extends to ora errata. High density of collagen fibrils, cells, proteins, a mucopolysaccharide filler substance.
363
Anterior Hyaloid
Extends from the vitreous base to attach to the lens.
364
Hyaloideocapsule ligament of Weiger
Strong circular adhesion between the anterior vitreous, posture zonules, and the posterior capsule of the lens.
365
Berger's space
Potential space between anterior hyaloid and the posterior lens capsule that is located in the central non-attachment area of Weiger.
366
Posterior hyaloid
From vitreous base to ON.
367
Cloquet's canal
AKA hyaloid channel or retrolental tract. A normal remnant of primary vitreous in the middle of the vitreous. Low density liquid fluid surrounded by high density. The former sight of the hyaloid artery.
368
What happens to the hyaloid artery
After birth it regresses to the optic disc where it becomes the CRA.
369
Area of Martegiani
The posterior end of cloquet's canal that is in contact with the OD.
370
Epicapsular star
On anterior lens capsule. It is the embryological remnant of the former connection between the tunica vasculosa lentil and the posterior hyaloid artery.
371
Mittendorf's dot
Embryological remnant of the hyaloid artery on the posterior lens capsule
372
Bergmeister's papillae
Embryological remnant of the hyaloid artery on the optic disc.
373
Function of RPE
Phagocytosis of Phot outer segments, Transfer of ions, water, and metabolites, Vitamin A storage, Blood retinal barrier, Absorbs light, produces growth factor.
374
Inner segment of photoreceptors
Produce photopigments that are transported to outer segment.
375
Myoid
The inner layer of inner segment. Makes protein.
376
Ellipsoid
The outer layer of inner segment. Packed with mito for energy.
377
Cilium
Connects the outer and inner segment.
378
Outer Segment
Stacks of membrane discs that contain photopigments.
379
OS of rods vs. cones
Disc membranes are continuous with disc in cones but are not in rods. (free floating)
380
Where is the rod density greatest
5 mm (20 degrees) from the fovea in an area known as the rod ring.
381
What wavelength does rhodopsin absorb maximally
507 nm
382
What do rods terminate in
Sphericals
383
Cyanolabe (blue)
440
384
Chlorolabe (green)
535
385
Erythrolabe (red)
565
386
Where is the fovea
5 mm temporal and 0.4 mm inferior.
387
ELM
Not a true membrane. Formed by mueller cels and inner segments of the photoreceptors
388
ONL
Contains the cell bodies of rods and cones
389
OPL
Synapses between Photo, horizontal, Bipolar.
390
Rod Spherule
Can synapse with 1-4 rod bipolar cell dendrites and horizontal
391
Con pedicule
Can form a synaptic triad (3 horizontal or 2 horizontal and one bipolar).
392
Who can cone pedicure synapse with
Midget, flat, or diffuse flat bipolar cells.
393
Henley's layer
The OPL in the macula
394
Where does OPL get is blood
booth choroid and retina.
395
Who does CRA supply
NFL, GCL, IPL, INL, OPL
396
Where does retinoschisis occur
OPL
397
Where are hard exudates located
OPL
398
INL
Cell bodies of bipolar, horizontal, interplexiform, amacrine, mueller cells.
399
Midget bipolar cells
Connect to only one cone and one ganglion. Resolve fine detail. Found in the fovea.
400
Flat bipolar cells
Connect with several photoreceptors
401
Diffuse flat bipolar cells
Connect with numerous cone receptors (more than flat)
402
Horizontal cells
Carry information laterally within the retina through synapse of photoreceptors, bipolar and other horizontal cells. Give inhibition.
403
Interplexiform cells
Rely information between the IPL and OPL
404
Amacrine cells
Connect bipolar, interplexiform, ganglion, and amacrine.
405
Mueller cells
Found from ILM to ELM. Provide structural and nutritional support.
406
Which cells in the retina are inhibitory
Horizontal and amacrine
407
Layers the receive blood from the CRA
NFL and INL
408
Inner Plexiform Layer
Amacrine cells synapse with self, bipolar, and ganglion.
409
Bipolar vs. amacrine cells
opposite effects
410
Ganglion Cell layer
Each ganglion cells has a single axon that travels and terminates in the lgn.
411
P-cells
Type of ganglion cells. Deal with color and fine detail.
412
Where in LGN do parvo axons go
3,4,5,6
413
P1 cells
Midget ganglion cells. Most common. Have only one dendrite that synapses with one midget bipolar cell that synapse with one cone in fovea.
414
P2 cells
Larger than P1 with multiple dendrites. Less common.
415
M-Cells
Type of ganglion cell. Sensitive to dim changes in illumination and motion.
416
What layer in LGN cells project
1,2,
417
NFL
Composed of the axons that collectively form the ON
418
Where is the ON thickest?
ISNT.
419
Papillomacular bundle
NFL fibers that extend from the temporal macula and to the ON.
420
CWS
(soft exudates) Located in the NFL
421
Splinter hemorrahges
(dance hemes) are in NFL. Occur with normotensive glaucoma
422
Flame hemorrhages
Within the NFL. Associated with retinal vascular pathology.
423
Dot blot hemes
Within the NFL
424
ILM
Formed by Muller cells.
425
ILM over disc
Astrocytes take over for muller.
426
Epiretinal membranes
Occur in the ILM and are commonly located in the macula.
427
Mueller Cells
Located in ILM to ELM. Provide structural and nutritional support. Aid in glycogen metabolism (store so photoreceptors always have nutrients), act as a buffer, and absorb and recycle metabolic waste products.
428
Fiber baskets
Although mueller not found within photo layer microvilli of the cells may extend and form a fiber basket
429
Astrocytes
Help form the ILM at the optic disc. Similar functions as mueller cells
430
Microglial cells
phagocytic cells that respond to inflammation or injury. Found everywhere.
431
Role of neuroglia cells in Retinal processing
NONE
432
Capillary networks in the retina
NFL and INL.
433
cilioretinal artery
Branch from the SPCAs of the choriocapillaris that supplies the inner layer of the retina. Present in 15-20% of population.
434
AV crossings
A and V share a common adventitia at crossings. Damage to the arterial wall results in venous wall compression and thrombus formation.
435
Macula diameter
5.5 mm or 18 degrees
436
Fovea
1.5 mm diameter (1DD).
437
How much of fovea is avascular
0.4-0.5 mm.
438
Foveala
0.35 mm in diameter and 0.13 mm in thickness. Has only photoreceptors.
439
What photoreceptors are not in the foveala
No blue cones or rods
440
Parafovea
0.5 mm zone that surround the fovea. Has all retinal layers. Thickest area of the retina.
441
Clivus
In parafovea. Sloping of the retinal layers.
442
Perifovea
1.5 mm zone. Occurs when ganglion cell layer becomes 4 cells thick. Boundary between perifovea and periphery occurs when ganglion cell is 1 cell thick.
443
CN V
Trigeminal. Sensation and mastication.
444
CN 8
Sensory. Hearing and balance.
445
CN 9
Glossopharyngeal. Both. Post 1/3 taste, swallowing, salivation, monitors carotid sinus.
446
CN 7
both. Facial expressions, lacrimation, salivation, ant 2/3 taste.
447
CN 10
Vagus. Both. Taste, swallowing, palate elevation, talking, thoracoabdominal viscera.
448
CN 11
Accessory. Motor. Head turn, shoulder shrug
449
CN 12
Hypoglossal. Motor. Tongue movement.
450
Where will the tongue devaiate
Towards the lesion
451
Where will the uvula deviate?
Away
452
What visual field does the optic tract carry
Information from the same side of the visual field.
453
What destinations does CN II Have
1. LGN 2. pretectcal nucleus (pupils) 3. Supeior colliculus (saccades)
454
MLF
Connect CN III nucleus to CN IV, VI, and CN VIII.
455
Which nucleus in CN III are ipsilateral?
MR, IR, IO
456
Which nucleus in CN III are contralateral?
SR
457
How many nucleus are there for the elevator?
ONE
458
Where doe CN III travel close to
Posterior communicating artery
459
Superior devision of CN III
SR, levator. Sympathetic fibers for mueller also comes.
460
Inferior division of CN III
Innervates the MR, IR, IO, iris sphincter, and ciliary muscle. Has parasympathetic fibers from the EW
461
Lesion of CN III
Eye down and out.
462
A CN III that contains the pupil
Suspicious of aneurysm.
463
What likely causes a pupil sparing CN III lesion
ischemia of the small blood vessels that nourish the inner fibers of CN III.
464
Which is the longest and skinniest CN
CN IV.
465
Where is CN IV located
At the midbrain by the inferior colliculus.
466
What is unique about CN IV's Path
ONLY cranial nerve to leave the dorsal side of the brain steam and cross to innervate the contraleral oblique.
467
SOURS
SO tilt to unaffected side. SR to same side.
468
Does CN IV go through the annulus of Zinn?
NO. It is superior.
469
Which are the only two muscles that receive innervation from the contralateral nucleus
SO and SR.
470
Division of the VI
Nasociliary, Frontal, Lacrimal
471
Nasociliary division of V1
Includes Infratrochlear, LPCA, SPCA, and ethmoid.
472
Frontal Nerve
Includes the supraorbital and supratrochlear.
473
Lacrimal Nerve of V1
Provides sensory feedback to the lacrimal gland.
474
Parasympathetic innervation to the lacrimal gland
The zygomatic (V2) carries parasympathetic fibers from CN VII from the ptergyopalantine ganglion to the lacrimal nerve of V1.
475
V2 Maxillary Division
Includes the infraorbital and the zygomatic nerve.
476
How does V2 enters the skulls
Foramen rotundum.
477
V3
Mandibular devision. Provides sensory innervation to lower face and motor innervation for mastication.
478
How does the abducens nerve travel?
Makes a tight bend over the petrous ridge of the temporal bone.
479
What can cause CN VI palsy
increased ICP or Internal carotid artery anurysm
480
Who travels closest to the internal carotid artery
CN VI
481
Course of CN VII
Starts in frontal lobe, travels to the pons, go through the internal auditory canal and through the geniculate ganglion and then branches into the greater petrosal nerve and the chords tympanic nerve and the others go to the face.
482
Greater petrosal nerve
Caries parasympathetic innervation to the lacrimal grand. Greater petrosal joins deep petrosal to form the vidian nerve that then goes to pterygopalantine ganglion and then join zygomatic branch that then communicates with V1.
483
Chords tympani n.
Carries taste fibers from the anterior 2/3 of the tongue and para to submandibular and sublingual glands.
484
Facial expression nerves
Main root of CN VII enters the parotid gland and divides into five branches to supply the muscles of the facial expression
485
Temporal branch of facial expression
Supplies procures, corrugated, occipital frontal, and orbicularlis oculi
486
Zygomatic branch of facial expression
Orbicularis occult.
487
Does CN VII innervate the parotid gland?
No the glossopharyngeal does. It just divides in there
488
What happens in the parotid gland
CN VII splits and the superficial temporal vein joins with the maxillary vein to form posterior facial vein.
489
Stroke
supra nuclear. Contralateral impaired innervation to he contralateral muscles of the lower face.
490
Bell's palsy
Lower motor neuron. Ipsilateral. Impaired innervation of upper and lower.
491
Where does parasympathetic innervation come from?
CN III and CN VII
492
Sympathetic innervation to the eyes?
Travels with ICA. Can branch to CN III for mueller, CN V1 to travel with LPCNs or SPCNs to iris dilator or choroidal and conj blood vessels, or blood vessels of the lacrimal n. by the vidian nerve.
493
1st order sympathetic fibers
Begin in hypothalamus and decent in C8-T2 to synapse in ciliospinal center of Budge
494
2nd order sympathetic fibers
leave the ganglion and travel around the clavicle an across the apex of the lungs before entering the superior chain ganglion
495
Post ganglionic fibers
Come from the superior chain ganglion and travel with ICA through carotid canal.
496
Where is the CSF?
subarachnoid.
497
Intraorbital potion of ON
surrounded by pia, arachnoid, and dura.
498
What surround the intracranial portion of the ON?
Only the pia mater.
499
Why do we get papilledema?
CSF fluid spreads into the ON.
500
What provides myelination after the lamina cribosa?
oligodendrocytes
501
Why is there pain on eye movement with lamina cribosa?
The SR and MR shares an optic sheath with the ON.
502
Can the optic nerve auto regulate?
Yes!
503
Where is the ON located
15 degrees from fixation
504
Is the On larger vertically or horizontally
vertically
505
What is the ILM for the ON
Astrocytes (not mueller)
506
How long is the ON
50-60 mm
507
Pre-laminar ON
Anterior to lamina cribosa. No myelin.
508
Intermediary tissue of Kuhnt
Separates ON tissue from rest of retina.
509
Border tissue of Jacoby
Separates the ON from the choid
510
Border tissue of elsching
Sclera collagen fibers surround glial tissue around the ON.
511
Intraorbital portion
30 mm. From lamina cribosa to exiting the skull. S-shaped. Myelinated.
512
Intracanalicular
6-10 mm. Through the optic canal in the cranium.
513
Intracranial
10-16 mm. Portion of the optic nerve extending from the optic canal to the optic chasm.
514
Anterior knees of wilbrand
Inferior nasal fibers that loop anterior into the contralateral track. AIC.
515
Posterior knees of wilbrand
Superior nasal fibers that loop posteriorly into the ipsilateral optic tract before crossing through the optic chasm. PIS.
516
Optic Track
Superior are medial side, Inferior are lateral. Macular are middle.
517
LGN layers
At the thalamus. Mango layers 1,2. Parvocellular 3-6. Koniocellular are between.
518
Uncrossed fibers of the optic synapse in
2,3,5
519
Crossed fibers of the optic synapse in
1,4,6
520
The orientation of different fibers
Superior are medial. Inferior are lateral.
521
Optic radiation inferior
Inferior radiations-fibers travel through the temporal lobe and around the lateral ventricle into the parietal lobe and form meter's loop
522
Optic radiation superior
Superior radiation-Course directly through inferior parental lobe and terminate in occipital lobe.
523
Optic radiation mnemonic
SPIT(M).
524
Calcimine fissue
Divides occipital lobe into anterior and posterior
525
Cuneus gyrus
Superior fibers terminate here
526
Lingual gyrus
Inferior terminate here
527
SCIL
Superior cuneus, inferior lingual.
528
Macula in V1
Project to the outer surface of the apex of the occipital lobe. Superior to cuneus and inferior to lingual.
529
Summary of inferior retinal fibers
lower fibers course laterally in optic tract to form milers loop and end in lingual gyrus.
530
Layer 4 of V1
Synapses between optic radiations and neurons in cortex. Sent to higher cortical area for processing
531
Layer 5 of V1
Send to superior colliculus
532
Layer 6 of V1
Provide feedback to lgn.
533
Ocular dominance columns
in V1. fibers from only one eye
534
Blood supply to optic chiasm
Circle of willis and branches of ICA
535
Blood supply to the optic tracts
Anterior choroidal branch of the middle cerebral artery
536
LGN blood supply
Suppled by anterior choroidal and posterior cerebral arteries
537
Optic radiation blood suply
Suppled by anterior choroidal, middle cerebral, and posterior cerebral
538
V1 blood supply
posterior cerebral artery and middle cerebral artery
539
Post chasmal lesion
Homonymous visual field defects on the same side.
540
Most posterior a post chasmal lesion is located the more ______ the defect is
congruous
541
Temporal lobe defects
Defect for inferior eye-->superior VF defect. Pie in the sky.
542
Parental lobe defects
Defects of superior eye-->pie on the floor.
543
Which VF results in asymmetrical OKN response?
Parietal
544
Is visual acuity affected in post chasmal lesions
No. Unless bilateral lesions are present. Only if both blood supplies to V1 are obstructed and that is rare.
545
Macular sparing homonymous hemianopsia
most commonly a stroke that affected middle or posterior cerebral but not both.
546
Macula only homonymous hemianopsia
Most likely a tumor that has compresses both blood supplies to the macula cortex.
547
Bitemperoal hemianopis
Pituitary gland tumor
548
Junctional scotoma
Optic chiasm lesion that gets central vision loss in one eye and anterior knee of wilbrand.
549
Vf defects that respect the horizontal midline
Lesions anterior to the chiasm
550
What are most homonymous hemianopsia due to ?
Strokes. (except macula only homonomoys hemianopsia)
551
ON lesions
Asymmetrical. Typically respect the horizontal median.
552
Retinal lesions
Asymmetrical. Will not respect any midline.
