exam 1 Flashcards
(56 cards)
what is the average size of optic nerve
whats considered small, large?
1.99 X 1.77
horizontally: 1.77
vertical: 1.99
small: <1.5
large: >2.22
axons from what cell form nerve fiber layer?
what about the optice nerve?
ganglion axons for both
whats the conversion factors when using slitlamp slit to measure optic nerve size
60 lens 1
78 lens1.1
90 lens 1.3
in mal inserted optic nerve what is raised or flat
temporal is flat nasal raised
Optic nerve is located in what cell layer
ganglion cell layer
what is the paillomacular bundle
whats its significance to GLC
bundle of macular fibers that enter temporally of the ON
damage occurs here before optic nerve
meninges
which meninges is made of
- thin collagen
-vascular CT
-dense CT
what space holds CSF
which meninges is made of
- thin collagen
arachnoid
-vascular CT
pia mater
-dense CT
dura matter
sub arachnoid space holds CSF
what nerve fibers decussates at the optic chiasm
nasal
intraocular segment
starts where and ends where?
whats its 2 sections
-where do these 2 sections start and end?
which section has glial or astrocytes bundles
intraocular segment
starts where and ends where?
ONH to the lamina cribosa
whats its 2 sections
1. prelaminar
HAS GLIAL AND ASTROCYTES
2. Laminar
-where do these 2 sections start and end?
1. prelaminar
optic nerve head to lamina crib
2. Laminar
globe to lamina cribosa
what ON segment is S shaped
intraorbital
what ON segment starts to be mylinated with what cells
intraorbital with oligodendrocytes
muscle attatchment occurs in what ON segment and what muscles
intraorbital MR SR
purpose of astrocytes
ion concention regulator
structure
glycogen storage
what ON segment goes through optic canal
intracanalicular
Intracranial ON segment extends from what to where
what is its surrounding structures
Intracranial ON segment extends from what to where
optic canal to the optic chiasm
what is its surrounding structures
-internal carotid art
-sphenoid sinus
-ACA anterior cerebral artery
list the shortest to longest ON structures
- intraocular
- intracanalicular
- intracranial
- intraorbital
name the blood supply to the optic nerve segments
- intraocular
-short posterior cilliary arteries
-circle of zinn haller
2.intraorbital
-pial
-central retinal artery
- intracranial
-anterior communicating art
-anterior cerebral artery
-internal carotid
ON sheath meningioma occurs in what segments
introrbital intracanalicular
f>M
optociliary shunt vssels (collaterals
ON head edema and atrophy
painless
tx radiation or excise or monitor
What ventricle is superior to optic chiasm
where is the pituitary in relation to the optic chiasm
3rd
pituitary is 1 cm below optic chiasm
where is the compression located with a pituitary adenoma
what kind of VF defect can occur
near decussation
bitemporal
LGN
location
function
shape
what cells synapse here
Binocular processing (Y/N)?
LGN
location
-thalamus
function
-process and filter to send to visual cortex
-NO BINOCULAR PROCESSING
shape
-cone
what cells synapse here
-ganglion
what layers of the LGN are
mangocellular
parvocellular
koniocelular
what cells are ipsi and contralateral
what layers of the LGN are
mangocellular
1-2
parvocellular
3-6
koniocelular
all
“see I , I see, I see/ CIICIC”
Contralateral - 1,4,6
ipsilateral - 2,3,5
where does binocular processing occur
what layer receives input and what layer fives inhibitory feedback
Brodman area 17 primary visual cortex
layer 4 recieves input from LGN
Layer 6 gives inhibitory feedback to LGN
there are 6 layers total
the primary visual cortex is seperated by what fissure.
what gyrus is inferior and superior
calcarine
cuneus gyrus upper portion
Lingual gyrus lower portion
