vision

Question 1

what are the 3 layers of the eye

Answer 1

1) retina
2) Uveal tract
3) Sclera

Question 2

Retina

Answer 2

• part of the CNS
• posterior aspect of the eye
• optic disk and fovea

Question 3

what is the fovea

Answer 3

concentration of axons in the retina that allow us to see in better detail

Question 4

what are the 3 components of the Uveal tract

Answer 4

• choroid
• Ciliary muscle
• Irus

Question 5

what is the purpose of the choroid

Answer 5

rich capillary bed for nourishment of the photoreceptors

Question 6

what is the ciliary muscle

Answer 6

muscular fibers that surrounds the lens

Question 7

what is the iris

Answer 7

does pupillary constriction

Question 8

what are the parts of the sclera

Answer 8

• outermost fibrous tissue
• cornea
• vitreous humor

Question 9

what is the function of the cornea

Answer 9

permit light to pass

Question 10

what is the function of the vitreous humor

Answer 10

cellular aqueous component
phagocytic cells are pick of debris

Question 11

fovea

Answer 11

center of the macula (small depression or pit)
sharp vision or detail is viral 50% of the information from the optic nerve

Question 12

what are the two types of photoreceptors in the retina

Answer 12

rods and cones
in the outer nuclear layer

Question 13

cones respond to

Answer 13

light

Question 14

rods respond to

Answer 14

dark

Question 15

where does the optic tract cross/ decussation

Answer 15

at the optic chiasm

Question 16

what does the primary visual pathway involve

Answer 16

CN 3, optic track and optic radiation

Question 17

what is the major target for the primary visual pathway

Answer 17

Lateral Geniculate Nucleus (LGN): where first synapse happens

Question 18

what is the secondary target for the primary visual pathway

Answer 18

optic radiation to the visual cortex

Question 19

pathway of the primary motor pathway

Answer 19

CN 2 takes sensory info of light coming in - goes to the lateral geniculate nucleus (90%) - from the LGN it does through optic radiation to the visual cortex where the brain is able to make a picture of what is being seen

Question 20

pupillary light reflex pathway

Answer 20

the optic nerve sends information from both retina (nasal and temporal) to the pretectum - pretectum relays to the edinger wastphal nucleus which will stay in unilateral CN 3 preganglionic fibers - CN 3 will turn to postganglionic in the ciliary ganglion - postganglionic CN 3 goes ti the iris to constricy the pupillary constrictor muscles

Question 21

Nasal (direct visual field)

Answer 21

comes from the temporal half of the retina that stays unilateral

Question 22

Temporal (peripheral vision)

Answer 22

comes form the nasal half of the retina. Crosses over at the optic chiasm

Question 23

monocular visual field (closing one eye)

Answer 23

field that is divides into four quadrants

Question 24

Binocular visual field (seeing with both eyes)

Answer 24

two foves focus on two visual hemi fields. Temporal fields are more extensive =

Question 25

left homonymous hemianopsia

Answer 25

defect in the right optic tract with results in loss of information processes of the right temporal retina and left nasal retina
the left side of each eye is lost

Question 26

what are some causes of left homonymous hemianopsia

Answer 26

stroke, tumors, TBI

Question 27

lesions in the primary visual pathway on the optic nerve

Answer 27

defect in monocular vision loss in which over side the lesion is on

Question 28

causes of lesions to the optic nerve

Answer 28

tumor, TBI, Glaucoma

Question 29

what is glaucoma

Answer 29

disease of the eye producing damage to the optic nerve