Taste

Question 1

Define the structure of a taste bud

Answer 1

Clusture of taste receptor cells (presynaptic and receptor cells) projecting cillia around a taste pore
Innervated by cranial nerve fibres

Question 2

What are the tongue’s two chemosensors?

Answer 2

Ion sensors and non-ionic sensors

Question 3

Only presynaptic neurons (which are sensitive to ions) can send signals to cranial nerves. So how do sweet, bitter, and umami tastes get through?

Answer 3

Receptor cells release ATP onto presynaptic cells and onto free nerve endings
Presynaptic cells release serotonin in response to ATP

Question 4

At the synapse with the cranial nerve fibre, presynaptic taste cells release NTs conveying information about which taste qualities?

Answer 4

All of them

Question 5

Which cranial nerves innervate the tongue?

Answer 5

VII and IX (shoutout to X in the throat)

Question 6

How does taste reach the brain?

Answer 6

Taste buds stimulate cranial nerves which all feed into Nucleus of solitary Tract (NST), which feeds into ventral posterior medial nucleus of thalamus (VPMN), which then projects into primary gustatory cortex

Question 7

How do the taste signals leave the tongue?

Answer 7

Via parallel pathways

Question 8

True/False? Taste thresholds vary with temperature

Answer 8

True

Question 9

True/False? Primary gustatory cortex activity is altered with hunger

Answer 9

False