Visual and Auditory Senses

Question 1

Cornea and lens

Answer 1

Cornea and lens are refractive surface.

Question 2

Retina and fovea

Answer 2

Retina in the back of eye, fovea is the center.

Question 3

Optic Nerve

Answer 3

Optic nerve connects brain, blind spot.

Question 4

Rods

Answer 4

scoptic vision, dark (sensitive to light), movement, more population, 3 types, found in peripheral vision, M cells (1 and 2 layers)

Question 5

Cones

Answer 5

photopic vision, color and detail, less population, 1 type, found everywhere but mostly in fovea, P cells (3-6 layers)

Question 6

Light-> photoreceptors ___________ in response to light -> then what?

Answer 6

Light-> photoreceptors hyperpolarize in response to light -> lower glutamate which doesn’t excite GABA in horizontal cells -> bipolar cells depolarize and you can see things because info is passed onto the brain

Question 7

No light -> photoreceptors __________ -> _______ glutamate which does what?

Answer 7

No light -> photoreceptors depolarize -> increase glutamate which excites GABA in horizontal cells -> bipolar cells hyperpolarize and get less information

Question 8

Explain Visual fields and vision.

Answer 8

nasal retina changes hemispheres at the optic chiasm

temporal retina info stays on the same side.

Hemispheres are contralateral to visual field!

Question 9

Geniculostriate pathway

Answer 9

LGN info -> striate cortex (V1) -> Region V2 (depth and specificity) -> DORSAL (how; motor) or VENTRAL (what; naming/ID)

Question 10

Cochlea

Answer 10

(Origin of Corti): spiral in the Inner Ear.

Question 11

What frequencies are tuned to thick parts of the cochlea? what about the apex?

Answer 11

Narrow thick= high freq and Apex= low freq.

Question 12

What are outer and inner hair cells in the cochlea?

Answer 12

Outer hair cells (stuck) vibrate ossicles and inner hair (cilia) vibrate as a result (short cilia= hyperpolarize and long cilia= depolarize)

inner hair= auditory receptors

Question 13

How do outer hairs defend inner hair?

Answer 13

Outer hair defends inner by tightening membrane and not moving.

Question 14

What is Wernicke’s area?

Answer 14

Wernicke’s area: speech (biggest in left hem)

Question 15

What is Primary Auditory Cortex (Herschel’s Gyrus)?

Answer 15

Primary Auditory Cortex (Herschel’s Gyrus): nonliteral language and music (behind lateral fissure and bigger in right hem)