GS Gustatory

Question 1

what is the TFS for salty

Answer 1

0.01M

Question 2

what is the TFS for sour

Answer 2

0.009M

Question 3

what is the TFS for sweet

Answer 3

0.01M

Question 4

what is the TFS for bitter

Answer 4

0.000008M

Question 5

what four structures make up the tongue

Answer 5

taste buds, taste receptor, microvilli, papillae

Question 6

where are taste buds located

Answer 6

groove like structures called papillae

Question 7

each taste buds contain how many taste cells

Answer 7

50-100 taste cells

Question 8

life span of mature taste buds

Answer 8

short lived

Question 9

how and where are mature taste buds regenerated

Answer 9

continuously and from basal cells

Question 10

apical microvilli of taste cells are exposed to saliva through where

Answer 10

the taste pore

Question 11

tasty substances are sensed where

Answer 11

microvilli

Question 12

taste substance is sensed at the microvilli and always induces what

Answer 12

depolarisation and action potential degeneration

Question 13

taste cell action potential releases what

Answer 13

neurotransmitters

Question 14

taste cell action potentials releases neurotransmitters which activates what

Answer 14

gustatory afferent fiber

Question 15

different taste stimuli use different

Answer 15

signal transduction methods

Question 16

salty sensing taste cells express what

Answer 16

amiloride-sensitive sodium channels
(ENaC sodium channels)

Question 17

sour sensing cells express what

Answer 17

proton-sensitive potassium leak channels

Question 18

sodium in salts enters through what

Answer 18

channel to depolarise the cell

Question 19

sour is the taste of what ion

Answer 19

acid (H+)

Question 20

Acid ions (H+) block what

Answer 20

potassium channels

Question 21

when acidic ions block potassium channels what does this do

Answer 21

reduce the gK and depolarising the cell

Question 22

potassium type salts also stimulate these cells because of

Answer 22

leak potassium channels and change in Ek

Question 23

bitter sensing taste cells use what receptors, and what are they coupled to

Answer 23

7-TM receptors
Various G proteins

Question 24

bitter sensation is a method for recognising what type of compounds

Answer 24

Toxic

Question 25

what are the family of related bitter receptors

Answer 25

T2 receptors

Question 26

when receptors couple to Gq what activates it
and what does it increase

Answer 26

PLC
increases Ca2+ through IP3

Question 27

some receptors couple to gustducin which activates what

Answer 27

cyclic nucleotide phosphodiesterase’s

Question 28

how do few bitter compounds work

Answer 28

directly blocking leaking potassium channels

Question 29

sweet sensing cells use what receptors
and coupled to what

Answer 29

7-TM receptors
Gs

Question 30

sugars act through what to produce cAMP

Answer 30

Gs

Question 31

once cAMP is produced by sugars what does it do

Answer 31

PKA phsophorylates and closes potassium leak, causing depolarisation

Question 32

artificial sweeteners bind receptors coupled to Gq which activate what

Answer 32

PLC to increase Ca2+ through IP3

Question 33

coding for taste
1. what will the stimulus activate
2. which will activate what and where

Answer 33

stimulus will activate one specific receptor, which will activate only one specific pathway to the CNS

Question 34

Pattern Code
1. stimulus will activate what

Answer 34

stimulus will activate all receptors in different manners and proportions, then CNS decodes the signal

Question 35

taste cell neurons increase their firing rate with increases in what

Answer 35

stimulus concentration

Question 36

responses from taste and smell are first combined in where

Answer 36

orbital frontal cortex

Question 37

OFC also receives input from where

Answer 37

the primary somatosensory cortex and the inferotemporal cortex in the visual pathway

Question 38

biomodal neurons in this area respond to what senses

Answer 38

taste and smell
taste and vision

Question 39

firing of these neurons is also affected by what

Answer 39

the level of hunger of the animal for a specific food