Visual System

Question 1

Fibrous layer
Vascular layer
Neural layer of the eye

Answer 1

Slera, cornea
Choroid, ciliary body, iris
Retina

Question 2

Sclera and cornea

Answer 2

Sclera is tough white part that is piereced by optic nerve and central artery of retina

Cornea is transparent

Question 3

Ciliary body

Answer 3

Anterior component of middle layer

Produces aqueous humor

Question 4

Iris

Answer 4

Pigmented muscular layer that have shpincter and dilator muscles

Question 5

Lens

Answer 5

Change shape via the ciliaris muscle

Question 6

Path of light throug hthe eye

Answer 6

Cornea
Aqueous humor 
Lens 
Vitreous body
Retina

Question 7

Neural layer

Answer 7

Retina is posterior and ora serrata is most anterior segment of it

Question 8

Optic disc

Answer 8

Basically the optic nerve

Where central artery of retina eminate

Question 9

Papilledema

Answer 9

Swelling of optic disk due to increased pressure

Question 10

Photoreceptor layer of retina

Answer 10

Photoreceptor cells convert light into APs

Question 11

Plexiform/neural layer

Answer 11

Interneurons
Bipolar - connect receptor cells to retinal ganglion cells
Horizontal cells - refine electrical signal to make it sharper (lateral inhibtion)

Question 12

Ganglion cell layer

Answer 12

OUtput cells of retina called the ganglion cells

Question 13

Rods vs. cones

Answer 13

Rods - good for movement and low levels of light…peripheral part…loss is night blindness

Cones - good for color…legally blind if lose these…higher in the macula and fovea

Question 14

Why is the fovea the best place for vision

Answer 14

Highest concentraiton of cones
Avascular
Axons bend away so not refracted

Question 15

On center vs. off center

Answer 15

When light hits middle of on-center, depolarizes

When liht hits periphery of off center, depolarizes

Question 16

Simple cells

Answer 16

Input derived from multiple ganglion cells

Create columns

Question 17

Optic radiations

Answer 17

From the LGN of the thalamus to the primary auditory cortex

Question 18

Besides the LGN, RGC project to

Answer 18

Superior colliculus and pretectal area

Question 19

Path of pupillary light reflex

Answer 19

Retina
Pretectal nuclei of MB
Parasympathetic nuclei of oculomotor nerve
Ciliary ganglion
Pupillary sphincter

Question 20

Binocular vision

Answer 20

Eliminates the blind spot and gives objects depht

Question 21

Superior and inferior visual fields

Answer 21

Inferior detected by superior retina

Superior by inferior

Question 22

Paths of superior and inferior fields

Answer 22

Inferior field passes in superior optic rdiation to the cuneus…parietal lobe

Superior field passes in Myers Loop (lateral optic radiation) to the lingula…temporal lobe

Question 23

Primary visual cortex orgsnization

Answer 23

Macula and fovea in the most posterior portion

Question 24

Monocular scotoma

Answer 24

Lesion to a certain part of the retina…will just be one tiny blob

Question 25

Monocular blindness

Answer 25

Lesion to the optic nerve prechiasmal

Question 26

Heternymous bilateral hemianopia

Answer 26

Temporal loss in each eye (optic chiasm)

Question 27

Contralateral homonymous hemianopia

Answer 27

Lesion to the optic tract/LGN…will lose entire contralateral field

Question 28

Contralateral superior quadrantanopia

Answer 28

Lesion to Myer’s loop

Lose contralateral superior portion of vision

Question 29

Contralateral inferior quadrantanpia

Answer 29

Lesion to superior optic radiation

Lose contralateral inferior portion of vision

Question 30

Macular sparing

Answer 30

Lesion of the primary visual cortex that spares the caudal pole

Question 31

Dorsal and ventral pathways

Answer 31

Dorsal pathway involves parietal occipital areas and oncerns the where of svision

Ventral involves the infratemporal areas and concerns the what of vision

Question 32

Frontal eye fields

Answer 32

In the cerebral cortex (BA 8)…get input from posterior parietal areas, infratemporal area,s and primary visual cortex

Efferent to gaze and superior colliculus

Question 33

Saccadic movement
Smooth pursuit
Vestbiuloocular
Vergence

Answer 33

Shift fovea to image rapidly
Keep moving image on fovea
Hold images still during short term head movements….controlled by vestbiuklar
Move eyes in opoostive directions to position image on the fovea

Question 34

Right way eyes

Answer 34

Lesions of cerebral hemisphere make eyes look away from the side of paraylysis (toward lesion)

Question 35

Wrong way eys

Answer 35

Increased activity cause it to look toward the side of paralysis (away from lesion)