special senses eyes Flashcards
1
Q
eye
A
3 layered sphere filled with fluid
2
Q
special features
A
fibrous tunic vascular tunic nervous (sensory) tunic lens anterior segment posterior segment
3
Q
fibrous tunic parts
A
sclera
cornea
conunctiva
4
Q
sclera
A
white
-avascular CT
5
Q
cornea
A
transparent
-avascular CT
6
Q
conjunctiva
A
- covers anterior sclera
- vascular mucous membrane
- when vessels dilate=bloodshot eyes
7
Q
vascular tunic parts
A
chorcoid
ciliary body
iris
pupil
8
Q
chorcoid
A
posterior
- contains melanin
- highly vascular
9
Q
ciliary body
A
anterior
-ciliary muscle and ciliary processes - focus the lens
10
Q
iris
A
coloured part of eye
11
Q
pupil
A
opening in iris
12
Q
nervous (sensory) tunic = retina parts:
A
- outer pigmented layer
- inner neural layer
- fovea centralis
- optic disc
13
Q
inner neural layer
A
3 layers of neurons:
- photoreceptors (rods and cones)
- bipolar cells
- ganglion cells (axons form optic nerve (cranial nerve II)
14
Q
fovea centralis
A
-where light is focused
=area of greatest visual acuity
-no rods, no cones
15
Q
optic disc
A
blind spot where blood vessels and optic nerve exit eye
no rods or cones
16
Q
lens
A
avascular, transparent
-cataracts=clouding of lens
17
Q
anterior segment
A
anterior to lens
- contains aqueous humour
- fluid similar to plasma
18
Q
posterior segment
A
posterior to lens
- contains vitreous humour
- gel-like
