chemical senses

Question 1

what is the role of hypothalamus and amygdala in human taste system

Answer 1

pleasure, aversion, food seeking, satiety, etc.

Question 2

cranial nerve for epiglottis

Answer 2

10

Question 3

taste in the fungiform papillae

Answer 3

sweet, umami

Question 4

taste in the circumvallate papillae

Answer 4

bitter

Question 5

foliate papillae taste

Answer 5

salt and sour

Question 6

nerve for circumvallate papillae

Answer 6

9

Question 7

cranial nerve for fungiform papillae

Answer 7

7

Question 8

describe the makeup of papillae

Answer 8

contain a few 100 taste buds, each taste buds have 50-100 taste receptors,

Question 9

are taste receptor cells neurons

Answer 9

no

Question 10

what do taste receptor cells synapse on

Answer 10

gustatory afferent axons

Question 11

which tastes have smaller taste thresholds

Answer 11

bitter and sour

Question 12

what is the taste transduction cascade for umami

Answer 12

tastants activate T1R1 and T1R3, alpha subunit activates PLCB2 which transforms IP3 from PIP2, IP3 opens a Calcium channel on the endoplasmic reticulum which releases calcium into the cytoplasm, calcium influx opens TRPM5 channel causing Na influx, robust depolarization occurs, Calcium modulator channel is opened from the intracellular calcium, ATP is released, PX2/PX3 channels open as a result of ATP as neurotransmitter on the taste nerves

Question 15

what is the taste transduction pathway for salty

Answer 15

amiloride sensitive sodium channels open due to salt tastants, depolarization occurs and flows downstream where it activates voltage-gated sodium, potassium, and calcium gated channels, calcium allows for transmitter release onto the taste afferents

Question 16

what is the taste transduction pathway for sour

Answer 16

hydrogen sensitive TRP channels open in response to sour tastants, the depolarization travels downstream to open sodium, potassium, and calcium channels, the channels result in more depolarization and stimulate neurotransmitter release onto the taste afferents

Question 17

what is the central taste pathway

Answer 17

taste buds, gustatory axons, medulla/brain stem, VPM thalamus, insular/frontal cortex, amygdala

Question 18

where are the collateral inputs of the medulla

Answer 18

hypothalamus and amygdala

Question 19

what happens if you ablate the P2X receptors

Answer 19

taste cells cannot depolarize and you cannot taste anything

Question 20

describe olfactory transduction

Answer 20

receptor binds odorant, alpha subunit turns gtp to gdp, adynyl cyclase activated, camp synthesized, camp channels opened for na and ca causing influx, calcium binds to ca gated cl channel causing an influx of cl, cell is further depolarized (most of depolarization

Question 21

describe olfactory repolarization

Answer 21

calcium begins to inhibit adynyl cyclase which decreases camp synthesization and decreases camp affinity of camp gated channels so some begin to close (by binding to CAM)

Question 22

what kinds of inputs do each glomerulus receive

Answer 22

each glomerulus receives input from olfactory neurons expressing specific receptor proteins

Question 23

describe the central olfactory pathways

Answer 23

olfactory receptor neurons synapse on the mitral and tufted cells in the glomureli (these make up the olfactory tract in the olfactory bulb). the olfactory tract extends to the pyriform cortex, olfactory tubercle, amygdala, and entorhinal cortex
-these project to the orbitofrontal cortex, thalamus, hypothalamus, and hippocampus

Question 24

what is the role of DAG in bitter sweet umami pathway

Question 25

what is the role of melastatin in sween umami pathway

Question 26

what g protein receptor is associated with bitter

Answer 26

T2R

Question 27

what g protein receptor is associated with sweet

Answer 27

T1R2, T1R3

Question 28

what g protein receptor is associated with umami

Answer 28

T1R1, T1R3

Question 29

what tastes is the TRPM5 channel associated with

Answer 29

bitter, sweet, umami

Question 30

how many types of T2R channels are there

Answer 30

30, most bitter taste receptor cells express most of them if not all

Question 31

where are the foliate papillae

Answer 31

sides of tongue

Question 32

where are the circumvallate papillae

Answer 32

back diamond of tongue, nine of them

Question 33

where are the fungiform papillae

Answer 33

front of tongue

Question 34

what is the most sensitive part of the olfactory receptor cell

Answer 34

the cillia

Question 35

what do we know about the loss of smell with covid 19

Question 36

what is the significance of temporal spiking

Question 37

where is the olfactory bulb

Answer 37

bottom of the frontal lobe near your nose

Question 38

what flavor corresponds to the glutamate tastant

Answer 38

umami

Question 39

what flavor corresponds to the quinine tastant

Answer 39

bitter

Question 40

what flavor corresponds to the sucrose tastant

Answer 40

sweet