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Flashcards in Midterm 1 Deck (282)
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1

Visual pathway order

retina, ON. chiasm, tract, lgn, radiations, striate cortex

2

synapse 1

PR cell
- photon strikes photopigment
-photopigment splits- chemical rxn produce message

3

synapse 2

bipolar cell
(between PR and Gang)

4

synapse 3

ganglion cell
axons (optic nerve) --> optic chiasm --> optic tract

5

synapse 4

LGN neuron
axon --> optic radiations

6

which part of the ON is the longest?

intraorbital

7

what part of the sphenoid does the ON go through?

lesser wing

8

list the parts of the ON from shortest to longer

intraocular < intracanalicular < intracranial < intraorbitll

9

how many fibers does the ON have

1-2.2 million

10

what is the horizontal diameter of ONH

1.5 mm (1500um)

11

what is the prelaminar part of the intraocular nerve

fascicles: sheats of astrocytes bundle ~1000 fibers per fascicle

12

what is the laminar part of the intraocular nerve

within the lamina cribosa

13

pathway of ganglion cells

ganglion cells from retina to LGN then become optic radiations

14

what is the lamina cribosa

network of sclera fibers where the ON exits the eye
- if IOP goes up --> damage to the perforated nerve fibers that are in the sclera

15

intraorbital portion of the ON diameter

3mm

16

intraorbital portion of the ON postlaminar

Fascicles acquire a connective tissue sheath and become myelinated by oligodendrocytes

-surrounded by EOMs

17

what is longer: globe or intraorbital

intraorbital is loner than the apex-apex measurement of the globe

18

what is between the fascicle in the post laminar part of the ONH

glial tissue is between the fascicle

19

why is the infraorbital portion of ON so long?

need wiggle room to look around

20

where is myelination only located?

post laminar

21

increases CSF affect on ON

push on it and it swells

22

which layer of the meningeal sheath has a lot of BV

PIa- helps profuse parts of the ON

23

what does glial tissue in the ON do

separates the nerve form the retina, choroid, sclera

24

Intermediary tissue (of Kuhnt)

Glial tissue separating the retina

25

Border tissue (of Jacoby)

Glial tissue separating the choroid

26

Marginal tissue (of Elschnig)

Connective tissue continuous with the sclera

27

what is the ON inferior to?

olfactory tract and anterior cerebral artery

28

what is the ON superior and medial to?

ICA

29

what is the ON lateral to?

sphenoid body

30

what is the sheath of the optic nerve attached to

sheath of EOM