Special sences CH 15 Flashcards Preview

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Flashcards in Special sences CH 15 Deck (66)
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1

Palpebae

Eyelids,

2

Conjunctiva

Transperent membrane that lines the eye lids and covers the inner (palpebral conjunctiva) and outer (ocular conjunctiva) surfaces of the eyes.
The fornix is a pocket of the eye where the two conjunctiva become continous

3

Lacrimal apparatus

Consists of:
lacrimal glands and ducts
paired lacrimal canaliculi
lacrimal sac
nasolacrimal duct

4

Lacrimal fluid

Contains lysosomes, mucus and antibodies

5

Extrinsic eye muscles

Control mevement of each eye:

6

Lateral Rectus

Moves eye laterally

7

Medial rectus

moves eye medially

8

Superior rectus

Elevates eye and turns it medially

9

Inferior rectus

Depresses eye and turns it medially

10

Interior oblique

Elevates eye and turns it laterally

11

Superior oblique

Depresses eye and turns it laterally

12

Diplopia

Seeing double because if uncoordinated eye muscles

13

Strabismus

Congentital weakness of the external eye muscles

14

3 layers of the eye

Fibrous layer
Vascular layer
Inner layer

15

Fibrous layer

The outermost coat, composed of dense connective tissue:
Sclera and Cornea
Supports and protects
Serves as attachment sight for the extrinsic eye muscles
Contains structures that assist in focusing

16

Sclera

Posterior portion of fibrous layer, glisining white, opaque. "white of the eye" Protects and shapes the eyeball and provides ancoring point for the eye muscles

17

Cornea

Transparent window, continuous with the sclera.
It allows light to enter the eye.
No blood vessels
Most sensitive portion of the eye

18

Vascular layer (uvea)

Pigmented middle coat of the eye has 3 regions:
Choroid
Ciliary body
Iris

19

Choroid

middle layer the encircles the eye between the retina and the sclera. lBlood vessel rich posterior portion, nourishes the eye and make malanocytes that protect the eye from the sun

20

Ciliary body

Anterior this ring that encircles the lens, controls lens shape and secretes fluid to fill the anterior cavity
Change focus from near to far

21

Iris

Anterior portion of the eye, colored part the contracts and dilates to control the amount of light that enters the pupil
pupillary constrictor and pupillary dilator

22

Inner layer

Innermost layer, retina, nervous layer:
Pigmented layer and Neural layer

23

Pigmented layer of the retina

Single cell think linning, absorb light and act as phagocyles, photoreceptor cell renewal.

24

Neural layer of the retina

Plays direct role in vision. 3 types of neurons: photoreceptors, bipolar cells, and ganglion cells

25

Optic disc

Weak spot in the eye where the optic nerve exits,

26

Rods and Cones

Rods: dim light and peripheral vision receptors
Cones: Color, bright light and HD

27

Internal chambers and fluids

Anterior chamber: Aqueuous humor
Posterior chamber: Vitreous humor

28

Lens

Bioconvex, transparent and changes shap to focas light on the retina.
Image is upside down and backwards
Brain re-orientates image

29

Myopia

Distant objects focus in front of the retina, Eye ball is too long
nearsightedness (can see near)

30

Hyperopia

Focus is beyond the retina
Eye ball is too short
farsightedness (can see far)