Taste and Smell

Question 1

pheromones

Answer 1

is a chemical signal released by 1 member of the species and sensed by another species to trigger an innate response.

Question 2

A specialized part of olfactory epithelium in animals called the a accessory olfactory epithelium does what?

Answer 2

the accessory olfactory epithelium. It sends projections to the accessory olfactory bulb which then sends signals to the brain.

Question 3

Within the accessory olfactory epithelium, you have a structure called the vomeronasal system.. what do they do

Answer 3

In vomeronasal system, there are basal cells and apical cells. They have receptors at tips.

Question 4

Molecule will come in and activate receptor on basal cell/apical cell here. Basal cell send signal down what pathway?

Answer 4

sends axon through accessory olfactory bulb to glomerulus, then mitral or tufted cell which eventually goes to the amygdala (part of the brain)

Question 5

Amygdala is involved with

Answer 5

Amygdala is involved with emotion, aggression, mating etc. In temporal lobe, also involved in memory/decision making, emotional reactions

Question 6

Signal transduction is where

Answer 6

Signal transduction is where the signal binds to the receptor, which binds to GPCR. Depolarization. The signal goes to the brain.

Question 7

In humans have vomeronasal organ, but no accessory olfactory bulb which means

Answer 7

we rely very little on pheromones.

Question 8

If your smell is knocked out/closed, you can’t

Answer 8

taste things as well.

Question 9

Smell is also known as

Answer 9

lfaction

Question 10

Area in nostril called the

Answer 10

olfactory epithelium (olfactory sensory cells)

Question 11

Separating the
olfactory epithelium from the brain is the

Answer 11

cribriform plate (bone with little holes that allow olfactory sensory to send projections to the brain).

Question 12

Above the cribriform plate is

Answer 12

an extension from the brain – olfactory bulb

Question 13

olfactory bulb is a

Answer 13

a bundle of nerves that sends little projections through the cribriform plate into the olfactory epithelium, which branch off

Question 14

All cells sensitive to benzene will fire to one olfactory bulb – called a

Answer 14

glomerulus – designation point for various sensory olfactory cells that are sensitive to the same molecule. For example, a benzene glomerulus.

Question 15

At the glomerulus, the receptors

Answer 15

then synapse on another cell known as a mitral/tufted cell that project to the brain. This organization is there because it’s easier for one cell to send a projection to the brain instead of thousands.

Question 16

How does a molecule bind to a receptor and cause an AP?

Answer 16

The molecule binds to the GPCR receptor on odor molecule -> GPCR on olfactory epithelia->G-protein dissociates and causes a cascade of events inside the cell->G protein binds to ion channel which allows cells outside the cell to come inside->opens and triggers an AP->goes to cribriform plate->glomerulus->activate mitral/tufted cellàsynapse to brain.

Question 17

100 of different olfactory epithelial each sensitive to one particular molecule. They all send projections to one glomerulus respective to their specialization. Then they synapse onto a mitral/tufted cell which signals to the brain.

Answer 17

Just the main idea no question or term just understand

Question 18

what doesn’t synapse on to thalamus

Answer 18

Smell (olfaction) and taste (gustation) doesn’t synapse onto the thalamus

Question 19

Smell (olfaction) and taste (gustation) are ipsilateral or contralateral.

Answer 19

ipsilateral

Question 20

vision/hearing/touch are ipsilateral or contralateral.

Answer 20

contralateral.

Question 21

The labeled-line theory of olfaction describes

Answer 21

a scenario where each receptor would respond to specific stimuli and is directly linked to the brain.

Question 22

The vibrational theory of olfaction

Answer 22

asserts that the vibrational frequency of a molecule
gives that molecule its specific odor profile

Question 23

Steric theory of olfaction, or shape theory

Answer 23

asserts that odors fit into receptors similar
to a lock-and-key.

Question 24

anosmia

Answer 24

inability to perceive order

Question 25

The pathway for olfaction goes from

Answer 25

the olfactory bulb to the amygdala and the piriform
cortex. From there the signal is transmitted to the orbitofrontal cortex.

Question 26

We have 5 main tastes

Answer 26

bitter, salty, sweet, sour, and umami (ability to taste glutamate).

Question 27

Taste buds, in turn,
are contained in structures

Answer 27

papillae

Question 28

anterior taste buds

Answer 28

are mushroom-shaped structures located on the tip and sides of the tongue, which contain taste buds. aka fungiform

Question 29

side taste buds

Answer 29

aka Foliate papillae are folded structures at the back of the tongue on both sides, which contain taste buds

Question 30

back taste buds

Answer 30

AKA Circumvallate papillae are flat mound structures that are found at the back of the tongue and contain taste buds.

Question 31

Filiform papillae do not contain

Answer 31

Filiform papillae do not contain taste buds and exist all over the tongue. The center of the tongue contains only filiform papillae. This is why stimulation of the center of the tongue does not cause a taste sensation, while the back and perimeter produce a broad range of taste sensations.

Question 32

Tastant

Answer 32

a substance that stimulates the sense of taste

Question 33

Gustducin

Answer 33

a protein associated with the sensation of taste

Question 34

Front 2/3rd tongue carries signals via

Answer 34

7th cranial nerve via the chorda tympani

Question 35

Posterior (Rear 1/3rd ) tongue carries signals

Answer 35

via the 9th and 10th cranial nerves
(glossopharyngeal and vagus)

Question 36

Labelled lines model

Answer 36

Each taste bud receptor has 5 axons, all which send separate taste information to different parts of the gustatory (taste) cortex. Remain separate to the brain. And they all synapse on diff parts of the gustatory (taste) cortex.

Question 37

Sweet, umami, and bitter cells rely on

Answer 37

GPCR receptors.

Question 38

Sour and salty rely on

Answer 38

ion channels.

Question 39

how do GPCR receptors pathway work for taste

Answer 39

Glucose binds GPCR, conformational change, G-protein dissociates, opens ion channels, cause cell to depolarize and fire an AP

Question 40

how do ion channels pathway work for taste

Answer 40

o Salty tastants bind to salt receptors which detect the presence of sodium ions and should not be chosen by the researchers.

o Sour tastants bind to sourness receptors that react with hydrogen cations (H+). Once H+ binds to the receptor, it closes the potassium channels.

Question 41

What happens if we put salty receptor inside a sweet cell?

Answer 41

Receptors in membrane bind to glucose. But let’s insert a salty receptor. Since axon from cell leads to brain, if NaCl comes in, it activates the receptor, + ions go inside, sweet cell depolarizes and fires AP, and brain interprets it as a sweet signal. Put a salty receptor in a sweet cell, can trick your brain into thinking salt is sugar!