ENT Physiology

Question 1

gustation =

receptor cells mainly in __

Answer 1

taste

taste buds

Question 2

taste bud = alternating __+__ with __ on surface and ___ below

Answer 2

receptor and support cells
microvilli
taste afferents

Question 3

life span of a taste receptor cell =

replaced from __

Answer 3

10days

basal cells in taste bud

Question 4

sites of taste buds =

Answer 4

tongue
palate
epiglottis
pharynx

Question 5

3 types of tongue papillae that contain taste buds =

Answer 5

fungiform, vallate and follate

Question 6

type of tongue papillae that doesnt contain taste buds =

Answer 6

fusiform - the most numerous type of tongue papillae

Question 7

tastant binding to receptor cell > ____ depolarise > AP in ___ > __+__ > ___ areas

Answer 7

cell ionic channels
afferents
brainstem and thalamus
cortical gustatory

Question 8

taste to posterior 1/3rd of tongue is sensed by __

Answer 8

CN IX

Question 9

taste to non-tongue taste buds is sensed by ___

Answer 9

CN X

Question 10

salty taste is stimulated by __

Answer 10

chemical salts esp. NaCl

Question 11

5 primary tastes =

Answer 11

salty, sweet, sour, bitter, umami

Question 12

sweet taste is stimulated by __

Answer 12

the chemical composition of glucose

Question 13

sour taste is stimulated by ____

Answer 13

acids with free H+

Question 14

bitter taste is stimulated by ____

Answer 14

alkaloids
poisons
toxins

Question 15

umami taste is stimulated by ___

Answer 15

amino acids esp. glutamate

Question 16

3 names of the abnormalities of taste that can occur __

Answer 16

ageusia (loss)
hypogeusia (reduced)
dysgeusia (distorted)

Question 17

olfactory mucosa consists of __+__+__

Answer 17

olfactory receptor cells, supporting and basal cells (secrete mucous)

Question 18

olfactory receptors = specialised endings of ___ each with a ____ and expanded end called an ___

Answer 18

renewable afferent neurons
thick short dendrite
olfactory rod

Question 19

___ project from olfactory rods (__-__ per neuron) and bind to ___

Answer 19

cilia
10-12
olfactants

Question 20

life span of olfactory receptors =

precursors =

Answer 20

2 months

basal cells

Question 21

axons of olfactory receptors collectively form afferent fibres of ___ pierce ___ and enter ___>___>olfactory areas in the ___ lobe

Answer 21

olfactory nerve
cribriform plate
olfactory bulb
olfactory tract
temporal

Question 22

for a molecule to be smelled must be __+__

Answer 22

volatile enough

sufficiently water soluble (to dissolve in mucus)

Question 23

early nasal sign of Parkinson’s

Answer 23

hyposmia

Question 24

humans perceive __-___ Hz

Answer 24

20-20k

Question 25

tympanic:oval window = __:__ =impedence matching air to liquid results in a __ gain of ___

Answer 25

18:1 | pressure 22x

Question 26

ventilation pathway for middle ear = | has _+_ parts

Answer 26

eustachian tube | bony and cartilagenous

Question 27

cartilagenous tube of eustachian tube is usually ___ it is opened by ___+___

Answer 27

closed | tensor veli palatini and levator palatine muscles

Question 28

dysfunction of eustachian tube causes middle ear __ pressure

Answer 28

-ve

Question 29

spiral lamina of the cochlea turns around ____

Answer 29

central modiolus

Question 30

scala media and scala tympani and vestibuli are filled with ___

Answer 30

media = endolymph | tympani and vestibuli = perilymph

Question 31

Na+ and K+ in endo and perilymph | distribution is actively maintained to __

Answer 31

endo = 5Na+ and 150K+ peri = 150 Na+ and 5K+ power sensory cells

Question 32

inner hair cells in cochlea are responsible for ___

Answer 32

sound perception - afferents> brain

Question 33

outer hair cells in cochlea are responsible for ___

Answer 33

regulatory function - efferents from the brain

Question 34

inner:outer hair cells in cochlea

Answer 34

1:3

Question 35

in hair cells: | sterocilia are arranged in ___ with tip links connecting them. Depolarise when bend towards the ___

Answer 35

height order | longest

Question 36

tonotropic organisation of the cochlea = | = __ to ___ frequencies detection

Answer 36

basilar membrane thickness decreases from oval window to round window high to low

Question 37

central pathways for hearing = __ (acronym) =

Answer 37

``` E COLI Eighth CN nucleus Cochlear nuclei superior Olivary complex Lateral Lemniscus Inferior colliculus > thalamus ```

Question 38

primary auditory cortex =

Answer 38

superior temporal gyrus Brodman areas 41/42

Question 39

otolith organs =

Answer 39

utricle and saccule

Question 40

5 vestibular end organs

Answer 40

maculae of utricle and saccule | ampullae of lateral, superior and posterior semicircular canals

Question 41

otolith organs: maculae have ___ projecting upwards into a ____ with ___

Answer 41

stereocilia gelatinous matrix otoconia (calcium carbonate crystals)

Question 42

purpose of otoconia

Answer 42

lend weight and therefore with gravity brain perceives movement on elevators (linear motion) /tilting

Question 43

firing in otolith organs stops/continues with linear motion and head tilt

Answer 43

stops with linear | continues with tilt

Question 44

in otoliths the stereocilia are orientated in ___ so ___ are perceived by hyper/depolarisation

Answer 44

all directions | all movements

Question 45

type 1+2 hair cells in the otolith organs resting potential changes depending on ___

Answer 45

bend to/from kinocilium

Question 46

organ of sensation that sit in SCC ampullae = | deflection is caused by ___

Answer 46

cupula | perilymph movement

Question 47

vestibulo-ocular reflex =

Answer 47

stabilises eye | if turn head right then right side is stimulated and left inhibited => eyes move left

Question 48

if vestibulo-ocular reflex is damaged =>

Answer 48

nystagmus | fast flick away from damaged side

Question 49

in abnormal stimulation of posterior semicircular canal nystagmus =

Answer 49

pupil bounces up and down and twists

Question 50

tumour that causes slow progressive loss of balance

Answer 50

vestibular schwannoma

Question 51

central pathways for balance: vestibular nuclei communications with outputs to _+_+_

Answer 51

``` vestibulospinal tract (motor to back leg and neck) medial longitudinal fasciculus and occular muscles medial lemniscus and thalamus to cerebrum ```