Neuro - Sensory systems

Question 1

what effects the rate of neurotransmitter release

Answer 1

stimulus strength
amplitude of generator potential
frequency of AP’s in afferent fibres

Question 2

what are the 2 ways a signal can be transmitted

Answer 2

specialised sensory neurone
specialised epithelial receptor

Question 3

what is a tonic receptor adapted for

Answer 3

continue to respond to respond for the duration of the stimulus
consistent rate of AP’s
slowly adapting
nociceptors

Question 4

what are phasic receptors adapted for

Answer 4

burst of AP at onset and end of stimulus
some touch receptors
(feeling your watch only when you put in on and take it off)

Question 5

what is a dermatome

Answer 5

region of skin innervated by the spinal nerve of a single nerve of a single dorsal root ganglion

Question 6

where are somatic nerves segmented into

Answer 6

region of the periphery that they innervate

Question 7

what is a receptive field

Answer 7

area of skin in which stimulation results in a change in rate of AP’s

Question 8

what is the size of a receptive field dependant on

Answer 8

number of sensory receptor and size of branching of the sensory afferent

Question 9

what does a higher density of sensory receptors equate to

Answer 9

smaller receptive fields
(your hands have a shit load of receptors so have small receptive fields)

Question 10

what is two point discrimination

Answer 10

ability to distinguish 2 simultaneously applied stimulants as separate
spatial acuity

Question 11

function of the dorsal column-medial lemniscal system

Answer 11

transmission pathway for touch to the body
1-3 order neurones transmit to somatosensory cortex

Question 12

function of the trigeminothalamic system

Answer 12

transmission pathway for touch to the face
via the thalamus

Question 13

feature of superficial receptors and name 2

Answer 13

high spatial acuity
meissner’s corpuscle
merkel’s disks

Question 14

features of deep receptors and name 2

Answer 14

low spatial acuity
ruffini’s capsule
pacinian corpuscle

Question 15

which receptors are phasic

Answer 15

meissner’s corpuscle
pacinian corpuscle

Question 16

which receptors are tonic

Answer 16

ruffini’s capsule
merkel’s disk

Question 17

function of the outer ear

Answer 17

amplifies sound pressure at 2-5kHz
localisation of sound source

Question 18

function of the middle ear

Answer 18

important for amplifying the sound wave

Question 19

why does the middle ear need to amplify sound

Answer 19

because the inner ear has an aqueous environment that dampens the sound waves

Question 20

structure of the basilar membrane

Answer 20

snake that gets wider
narrow to wider to allow for distinction of different frequencies

Question 21

how does the basilar membrane work

Answer 21

movements of vibrational energy causes the stereocilia in the cochlea to either undulate upwards or downwards

Question 22

what do hair cells in the cochlea release

Answer 22

glutamate at the basolateral surface

Question 23

function of the inner hair

Answer 23

afferent inputs
signals to CNS

Question 24

function of outer hair

Answer 24

receives efferent signals from the CNS
modulates their activity

Question 25

what is a ribbon

Answer 25

cytoskeletal specialisation allows organisation of vesicles for faster neurotransmitter release

Question 26

what are tip-links

Answer 26

link together stereocilia co-ordinates their movement distortion leads to open ion channels

Question 27

what are stereocilia bathed in

Answer 27

endolymph - high in K+

Question 28

what are base bathed in

Answer 28

bathed in perilymph - low in K+

Question 29

how do outer hair cells respond to electrical signals

Answer 29

contract - depolarisation expand - hyperpolarisation

Question 30

what is a feature of auditory nerve cells

Answer 30

they are bipolar

Question 31

where are auditory nerve cells located

Answer 31

spinal ganglion

Question 32

where does information from both ear reach

Answer 32

both sides of the superior olive

Question 33

where is the vestibular system located

Answer 33

inner ear

Question 34

what is the vestibular system composed of

Answer 34

saccule utricle semi-circular cannals

Question 35

what types of semi-circular cannals are there

Answer 35

superior posterior horizontal

Question 36

what is the vestibular system attached to

Answer 36

the cochlea they share fluids and ionic profile

Question 37

what are the utricle and saccule classified as

Answer 37

otolith organs

Question 38

where are vestibular hair cells located

Answer 38

utricle saccule ampullae of semi-circular cannals

Question 39

what occurs at vestibular hair cells at rest

Answer 39

tonic release of neurotransmitters β-waves some ion channels still open

Question 40

what is the macula

Answer 40

sensory epithelium

Question 41

what overlays the stereocilia

Answer 41

otolithic membrane

Question 42

what is the otoconia

Answer 42

crystal structure embedded in the otolithic membrane makes it more dense allows it to respond to gravity

Question 43

what is the striola

Answer 43

hair cell positioning is mirrored, striola is in the middle (short-long (striola) long-short)

Question 44

what is the purpose of mirrored hair cell positioning

Answer 44

creates differential pattern of excitability if head tilts one way - hairs will move from short to long on side and vice versa on the opposite side causes difference in polarisation

Question 45

what does the utricle and saccule detect

Answer 45

utricle - horizontal movements saccule - vertical movements

Question 46

what do semi-circular cannals detect and how

Answer 46

head rotation endolymph flow displaces cupula

Question 47

what is the vestribulo-ocular reflex

Answer 47

reflexively move your eyes in the opposite direction as your head

Question 48

what is oscillopsia

Answer 48

caused by damage to the vestibular system results in 'bouncing vision'