Orbits & Eyes Flashcards Preview

Jason's Neuro Block > Orbits & Eyes > Flashcards

Flashcards in Orbits & Eyes Deck (36):
1

What is a blow out fracture of orbit? How and what is fractured? what does patient report?

trauma
fracture to ethmoid or lacrimal bone with entrapment of ocular muscles = double vision

2

What bones make the medial wall of orbit?

Maxilla
lacrimal
ethmoid
body of sphenoid

3

What bones make the lateral wall of orbit?

zygomatic
greater wing sphenoid

4

What bones make the floor of orbit?

maxilla
zygomatic

5

What bones make the roof of orbit?

frontal
lesser wing sphenoid

6

what are 3 layers to eye?

1. sclera/cornea
2. vascular
3. neural

7

sclera means? How?

tough
predominantly collagen laid down in concentric circles

8

What attaches to sclera?

extraoccular eye muscles

9

What does the Cornea do?

principal refractor ~60%

10

5 layers of cornea?

1. Epithelium (mucus membrane)
2. Bowman's layer
3. stroma (collagen)
4. Descemet's membrane
5. endothelium (cells don't divide)

11

describe cornea histologically?

avascular
transparent

12

How is the cornea transparent?

very organized parallel collagen fibrils creating destructive interference

13

is the sclera transparent or opaque? why?

opaque
non ordered/non-uniform size of collagen

14

where is the anterior chamber?

between iris and cornea

15

what is the anterior chamber angle for?

aqueous humour drains out

16

Where in the anterior chamber angle does aqueous fluid drain out?

trabecular meshwork through the canal of Schlemm

17

What is the Uvea? 3 things

1. Ciliary body (makes aqueous humour)
2. chroid
3. iris

18

3 things ciliary body does: which cells do what?

1. make aqueous humour (epithelium)
2. tethers lens (ciliary processes)
3. accommodation (ciliary muscle)

19

How is intraocular pressure created?

via ciliary body making aquenous humour

20

What are zonules?

ligaments that attach ciliary processes to the lens.

21

what does the ciliary muscle do? describe it's neural connections

focuses by changing lens shape
parasympathetic
smooth muscle

22

where do you find the ciliary muscle?

within ciliary body

23

what is presbyopia?

loss of lens accommodation/flexibility with age

24

2 muscles what control pupil: how innervated?

1. sphincter pupilae, ParaS, CNIII
2. dilator pupilae, Symp

25

What is the choroid?

3 layers of blood vessels under the retina that keeps it alive

26

what is the most important layer of choroid?

choriocapillaris just underneath retina

27

What is the fovea?

highest area of concentrated cones, no rods, HIGH visual acuity

28

what is the macula?

area around fovea with decreased vasculature, mostly from choroid

29

what is the orra serrata?

junction between retina and ciliary body

30

what is the lamina cribosa?

a structure continuous with the sclera that runs perpendicular and through the optic nerve, contains sieve-holes that transmit nerve fibres

31

where are the retinal artery and vein located?

in or along the optic nerve

32

curtain come down over someone's vision is most likely?

arterial ischemia/occlusion of central retinal artery

33

what are the vessels you see in the fundoscope?

central retinal artery

34

3 ciliary arteries are?

long posterior
short posterior
anterior ciliary

35

What are the 2 arteries what supply the retina?

1.Central retinal artery: inner
2. posterior ciliary: outer

36

2 Muscles of the orbits and their innervation?

1. orbicularis oculi (CNVII)
2. levator palpebrae superiosis (CNIII)
They work in opposition