Taste, Gustation

Question 1

Taste bud sensory receptors
Umami
Sweet
Bitter

Answer 1

Umami: T1R1 + T1R3 taste receptor 
Sweet: T1R2 + T1R3 taste receptors
Bitter: T2R 
Stimulation:
Gq -> phospholipase C - IP3 - Calcium release - Neurotransmitter release - action potential of neuron

Question 2

Taste bud sensory receptors
Salty
Sour

Answer 2

Salty: ENaC - Na+ channels = influx = depolarization
Sour: Proton sensitive ENaC
Opening of VGCC: calicum influx - neurotransmitter release - action potential

Question 3

Taste pathway

Answer 3

Facial, glossopharyngeal, vagus nerve
= chorda tympani CNVII
- pseudounipolar neurons - respective ganglia of CN - VPM in thalamus - insula - post central gyrus