Physiology of Taste and Smell

Question 1

what type of receptor is responsible for taste and smell?

Answer 1

chemoreceptors

Question 2

where are the sensory receptors for taste and smell primarily located?

Answer 2

tastebuds

Question 3

what are the sense organs for taste?

Answer 3

tastebuds

Question 4

where are the tastebuds primarily located?

Answer 4

papillae on the tongue
palate
epiglottis
pharynx

Question 5

lifespan of tastebuds?

Answer 5

10 days

Question 6

what nerves are involved in taste sensation?

Answer 6

CN7
CN9
CN10

Question 7

what do the axons of olfactory receptors form?

Answer 7

afferent fibres of the olfactory nerve

Question 8

what influences taste perception?

Answer 8

information from olfactory receptors

Question 9

name the 2 types of cells present in the taste bud

Answer 9

sensory receptor cells

support cells

Question 10

what cells are responsible for replacing old taste receptor cells?

Answer 10

basal cells

Question 11

what is the only type of papillae not to contain tastebuds?

Answer 11

filliform

Question 12

name the 4 types of papillae from anterior to posterior

Answer 12

filliform
fungiform
foliate
vallate

Question 13

which is the most numerous of papillae on the tongue?

Answer 13

filliform

Question 14

how does the taste signal get to cranial nerves?

Answer 14

tastant binds to receptor cells in the taste bud = depolarisation
causes AP in afferent nerve fibres which is conveyed to cranial nerves

Question 15

where is the end-point of the taste signal?

Answer 15

cortical gustatory cortex

Question 16

where does CN8 receive taste fibres from?

Answer 16

anterior 2/3rds of tongue via chorda tympani nerve

Question 17

where does CN9 receive taste fibres from?

Answer 17

posterior 1/3 of tongue

Question 18

where does CNX receive taste fibres from?

Answer 18

anywhere other than the tongue

Question 19

name the 5 primary tastes

Answer 19

sweet
salty
sour
bitter
umami (meaty/savoury)

Question 20

what is ageusia?

Answer 20

loss of taste function

Question 21

name given to reduced taste function?

Answer 21

hypogeusia

Question 22

name given to distortion of taste function?

Answer 22

dysgeusia

Question 23

causes of taste abnormalities/function?

Answer 23

glossutus
gum infection
tooth decay
URTI
meds
chemo
neoplasm

Question 24

3 cell types present in the olfactory mucosa?

Answer 24

olfactory receptor cells
supporting cels
basal cells

Question 25

what cells of the olfactory mucosa secrete mucus?

Answer 25

basal cells

Question 26

organise the structure of an olfactory neurone from proximal to distal:

olfactory receptor
dendrite
olfactory cilia
olfactory bulb

Answer 26

bulb
receptor
dendrite
cilia

Question 27

lifespan of olfactory recpetors?

Answer 27

2 months

Question 28

which part of the olfactory dibres forms afferent fibres of olfactory nerve?

Answer 28

axons of olfactory receptors

Question 29

what do olfactory bulbs do?

Answer 29

transmit smell information to brain

Question 30

what to the neurons after the olfactory bulb?

Answer 30

pass along olfactory tract to temporal lobe

Question 31

by what process do odorants reach the smell receptors in passive breathing?

Answer 31

diffusion

Question 32

how can the process of smell be sped up?

Answer 32

sniffing

Question 33

define anosmia?

Answer 33

inability to smell

Question 34

what is hyposmia

Answer 34

reduced abiity to smell

Question 35

what abnormality of smelling could indicate early parkinsons?

Answer 35

hyposmia aka reduced ability to smell

Question 36

how would you define an altered sense of smell medically

Answer 36

dysosmia