Vision

Question 1

Eyelids

Answer 1

separated by the palpebral fissure

meet at medial and lateral angles (canthi)

Question 2

lacrimal caruncle

Answer 2

reddish elevation at the medial canthus

Question 3

tarsal plates

Answer 3

connective tissue within the eyelids

Question 4

Levator palpebrae superopris muscle

Answer 4

moves upper eyelid

Question 5

conjenctiva

Answer 5

transparent mucous membrane

Question 6

larimal apparatus

Answer 6

keeps the surface of the eye moist.
lacrimal gland
larimal punctum
larimal canaliculus
lacrimal sac- fluid empties into nasal cavity
nasolacrimal duct
inferior meatus

Question 7

Eye Muscles

Answer 7

lateral rectus- lateral-abducens
medial rectus-medial-oculomoter
superior rectus- elevates, medial turn- oculomotor
inferior rectus- depresses, medial turn- oculomotor
inferior oblique- elevates, lateral turn- oculomotor
superior oblique- depresses, lateral turn- trochlear

Question 8

Posterior Segement of Eye

Answer 8

divided by ciliary zone and lens
filled with vitreous humor- clear jelly like
transmits light 
supports posterior surface of the lens
helps maintain intraocular pressure

Question 9

Anterior Segment of Eye

Answer 9

contains both anterior and posterior chambers
anterior chamber- between the cornea and iris
posterior chamber- between iris and lens
both filled with aqueous humor

Question 10

Glaucoma

Answer 10

increased pressure in anterior segement due to slow draining aqueous humor. causes compression of retina and optic nerve

Question 11

Lens

Answer 11

thick transparent, biconvex disc
held in place by ciliary zonule
elongated lens fibers form bulk of lens
lens gets bigger throughout life

Question 12

Light bending structures

Answer 12

lens, cornea, humors

Question 13

accomodation

Answer 13

curvature of the lens is adjustable which allow focusing on nearby objects

Question 14

Wall of eye- fiborous layer

Answer 14

most external
dense connective tissue
sclera and cornea

Question 15

sclera

Answer 15

posterior 5/6 of the tunic
white region
provides shape and anchor for the eye muscles

Question 16

cornea

Answer 16

anterior 1/6 of eye
connected to sclera by the limbus
has epithelium and endothelium
avascular but gets O2 from environment
many sensory nerves, much are pain receptors

Question 17

scleral venous sinus

Answer 17

allows aqueous humor to drain

Question 18

Wall of eye- vascular layer

Answer 18

middle layer
choroid
cilliary body
iris

Question 19

choroid

Answer 19

vascular
dark pigmented
posterior 5/6 of vascular tunic
brown
prevents scattering of light rays within the eye
choroid corresponds to the arachnoid and pia maters

Question 20

Ciliary Body

Answer 20

thickened ring of tissue which encircles the lens
mainly smooth muscle that focuses lens
made of :
ciliary processes and ciliar zonule (suspensory ligament- halo of fine fibers around lens)

Question 21

Iris

Answer 21

colored part

smooth muscle, attached to ciliary body

Question 22

pupil

Answer 22

round central opening
sphincter pupillae muscle (circular)
dilator pupillae muscle (radial)

Question 23

Wall of Eye- inner layer

Answer 23

retina

optic nerve

Question 24

Retina

Answer 24

deepest. 
2 layers:
pigemented- outer
neural- inner, has nervous tissue
photoreceptor cells, bipolar cells and ganglia (acramine and horizontal sometimes)

Question 25

macula lutea

Answer 25

contains mostly cones

Question 26

fovea centralis

Answer 26

only cones. visual acuity

Question 27

optic disc

Answer 27

blind spot

Question 28

rods & cones

Answer 28

``` rods- sensitive to light cones- color both have 2 segments outer- receptor region inner- generate nerve impulse ```

Question 29

Visual pathway to cerebral cortex

Answer 29

optic nerve--> optic chiasm--> optic tract--> lateral geniculate nucleus of thalamus--> optic radiation--> primary visual cortex

Question 30

visual pathways to other parts of the brain

Answer 30

midbrain: superior conlliculi: controls extrinsic eye muscles pretectal nuclei: mediate pupillary eye reflexes suprachiasmatic nucleus

Question 31

Blood supply to retina

Answer 31

outer 1/3 gets it from caps in choroid | inner part gets it from central artery

Question 32

cataracts

Answer 32

lens becomes opaque. people over 50

Question 33

macular degeneration

Answer 33

buildup of deposits in the retina causing loss of vision in the macula which is the center of the visual field

Question 34

trachoma

Answer 34

contagious infection from chlamydia of conjunctiva. causes the eyelids to become distorted and inverted causing eyelashes to scrape against cornea. leads to scarring and blindness.