BioCog 4A hearing and somatosensation

Question 1

what are sounds?

Answer 1

• air pressure

- compressed or rarified air

Question 2

pitch

Answer 2

= frequency

Question 3

timbre

Answer 3

= complexity of the wave

Question 4

loudness

Answer 4

= amplitude

Question 5

analytic organ

Answer 5

• the ear

- we can hear individual frequencies

Question 6

synthetic organ

Answer 6

• the eye

- we can only see the whole

Question 7

external ear

Answer 7

• pinna = ear shell

- external auditory channel

Question 8

middle ear

Answer 8

• tympanic membrane = eardrum
• tympanic cavity
• auditory ossicles
  (- round and oval window)

Question 9

internal ear

Answer 9

(- round and oval window)

- cochlea = snail house

Question 10

8th cranial nerve

Answer 10

= ear nerve

Question 11

outer hair cells

Answer 11

• only for amplification

Question 12

inner hair cells

Answer 12

• for actual hearing
• cilia
• located in organ of corti

Question 13

cilia

Answer 13

• ordered by size

- connected by tip links

Question 14

tip links

Answer 14

• bending leads to hyper- or depolarisation

Question 15

high and middle tone coding

Answer 15

• place coding

Question 16

low tones

Answer 16

• rate coding

- loudness by number of neurons

Question 17

left right location

Answer 17

• by disparity of the ears

Question 18

frequency-tonotopic map

Answer 18

• frequencies in the ear correspond to frequency representation in the brain

Question 19

high, low, front and behind location

Answer 19

• by timbre

- changes due to shape of pinna

Question 20

cochlea nucleus

Answer 20

• first after cranial nerve

- leads to superior olivary complex

Question 21

superior olivary complex

Answer 21

• after cochlea nucleus

- leads to inferior colliculus

Question 22

MGN

Answer 22

• medial geniculate nucleus
• after superior olivary complex
• leads to primary auditory cortex

Question 23

primary auditory cortex

Answer 23

• gets signals from MGN

Question 24

what

Answer 24

• ventral stream
• auditory cortex
• inferior frontal gyrus

Question 25

where

Answer 25

• dorsal stream
• superior parietal cortex
• superior frontal gyrus

Question 26

variants of somatosensation

Answer 26

• touch
• nociception = pain
• temperature
• organs (not aware all the time)
• propriocetpin = stretching of skin (not aware all the time)

Question 27

Merkel’s disks

Answer 27

• press on skin

Question 28

Meissner and Ruffini corpuscle

Answer 28

• low frequency vibrations

Question 29

open nerve endings

Answer 29

• pain

- temperature

Question 30

Pacinian corpuscles

Answer 30

• high frequency vibrations

Question 31

transduction in Paccinian corpuscles

Answer 31

• opening of displacement rings
  (- only reacts to changes)
• opening of Na+ channels

Question 32

intensity coding

Answer 32

• firing rate

Question 33

receptive fields

Answer 33

• the smaller the higher the resolution

Question 34

second-order neurons

Answer 34

• combine signals from receptor neurons (of receptive fields)

Question 35

dermatome

Answer 35

• part of skin connected to one spinal nerve

- 31

Question 36

spino-thalamic tract

Answer 36

• nociception and temperature
• withdrawal response before cogntion
• leads to medial lemniscus

Question 37

medial lemniscus

Answer 37

• merges dorsal colums and spino-thalamic tract

- leads to thalamus ventral posterior

Question 38

dorsal column

Answer 38

• touch

- leads to medial lemniscus

Question 39

thalamus ventral posterior

Answer 39

• after medial lemniscus

- leads to post centra gyrus

Question 40

tissue damage and inflammation

Answer 40

• detected by signalling molecules
• triggers cleeaning of damaged cells and
• release of signaling chemicals

Question 41

somatotopic map

Answer 41

• regions of body corresponding to regions in brain

Question 42

humnuculus

Answer 42

• distorted human image of somatosensation