Lecture 2

Question 1

the functions of taste

Answer 1

• gatekeeper of internal system
• each taste has particular function (sweet detect energy, salty maintain electrolyte, bitter for warning/ limit intake, sour guarding ph level, umami motivate protein intake)

Question 2

anatomy of gustatory system

Answer 2

tongue –> gustatory papilla –> taste buds –> taste receptor cells

Question 3

4 forms of papillea

Answer 3

1. cicrumvallate (largest, in the back)
2. foliate, side/back
3. fungiform, most rich, in the front
4. filiform (don’t contain taste buds/perception)

Question 4

labeled line theory

Answer 4

1. taste buds contain taste receptors cells, each cell coding for an unique taste quality
2. each cell connected to corresponding taste nerve fibre
   - 1 nerve, 1 taste quality

Question 5

across fiber theory

Answer 5

1. each taste receptor cell can identify multiple taste qualities and all come together in one specific nerve
2. each taste receptor tuned to one quality, but nerve fibers are connected to various cells

• or receptors cells or nerves are broadly tunes for all taste qualities

Question 6

transduction pathways

Answer 6

taste receptors: protein belonging to the GPCR family
- sweet: T1R1T1R2 family
- umami: T1R1T1R3 family
so some how they evaluated from each other
- bitter: T2R’s
- salt & sour: via ion channels

Question 7

3 crinial nerves

Answer 7

1. number 7: facial nerve, chorda tympani branch
   - serves front part of the tongue
2. number 9: glossopharyngeal nerve
   - serves back/sides of the tongue (swallow/spit)
3. number 10: vagal nerve
   - signaling that food is on it’s way

Question 8

from tongue to brain

Answer 8

1. goes to nucleas of the solitary tract (in brain stem)
2. then goes to anterior insula & frontal operculum (primary taste cortex)
3. further processing in orbitofrontal cortex (secondary gustatory cortex)
   - olfacotry goes here as well, multiple senses

Question 9

taste dimenions

Answer 9

• quality, identification
• sensitivity, detection
• intensity
• hedonic, liking

Question 10

individual differences of taste

Answer 10

• intensity: curve goes up, but differs quite a lot
• taste blindness: YAS2R38: taste nothing or bitternes
• order effects, frame of reference, context matters