Hearing, Smell, Taste- Taste Flashcards
1
Q
What are the 5 tastants?
A
- salty
- sour
- sweet
- bitter
- umami
- each has its own receptor, so 5 taste receptors
2
Q
What are clusters of taste receptor cells?
A
- taste buds
- clusters of 50-150 taste receptor cells
3
Q
Where are taste buds located?
A
- located on sides of taste pores between papillae (bumps)
4
Q
Papillae are specialized for specific tastants: T/F
A
false- they are not specialized for specific tasants
5
Q
Where are circumvallate papillae located?
A
back of tung
6
Q
where are foliate papillae located?
A
along the sides of the tongue
7
Q
Where are fungiform papillae located?
A
in the front of the tongue
8
Q
Are taste cells neurons?
A
- no
- do not have action potentials
9
Q
How often are taste cells replaced?
A
every 10-14 days
10
Q
Taste transduction
A
- receptors o cillia are bound by tastants
- receptor activation produces receptor potentials (like EPSPs)
- Instead of an action potential, receptor potential releases neurotransmitter onto Glassopharyngeal cranial nerve
- Thalamus, then cortex
- there is a gustatopic map in cortex
11
Q
Salty
A
Na+ ions flow through open ion channels in the taste cell membrane, causing depolarization
12
Q
Sour
A
- we perceive acidic solutions as sour (acid=high concentration of H+)
- Acid sensitive K+ ion channels are blocked, preventing K+ leaving the cell and leading to depolarization
13
Q
Sweet
A
- Sugars bind to TIR2 and TIR3 receptors, causing them to join (dimerize)
- Tastant binding to receptor -> activation of G-protein ->second messengers->Ca+2 flow into cell ->receptor potential -> NT release
14
Q
umami
A
- amino acid receptor (mostly activated by L-glutamate and monosodium glutamate)
- g-protein coupled metabotropic-like receptor; heterodimer of TIR1 and TIR3
- Tastant binding to receptor->activation of G-protein->second messengers->Ca+2 flow into cell -> receptor potential ->NT release
15
Q
Bitter
A
- T2R receptors: G-protein coupled metabotropic-like receptors
- Tastant binding to receptor->activation of G-protein->second messengers->Ca2+ flow into cell ->receptor potential-> NT release
