Chapter 8: The Chemical Senses

Question 1

What are the tastes that we recognize (4)?

Answer 1

1. sweetness
2. saltiness
3. sourness
4. umami “deliciousness”

Question 2

Sweetness can be recognized at the […] while biterness is at the […].

Answer 2

tip of the tongue; back of the tongue

Question 3

Papillae

Answer 3

small surface projections that contain many taste buds

Question 4

Each taste bud has […] taste receptors.

Answer 4

50-150

Question 5

Threshold concentration:

Answer 5

point at which a substances concentration can be recognized as a taste

Question 6

Great increase of concentration leads to a decrease in […].

Answer 6

selectivity

Question 7

A great increase in concentration leads to a decrease in selectivity.

Why is this the case?

How are they then distinguished?

Answer 7

common phenomenon in senses; their excitation leads them to be indiscriminate; more than 90% of receptor cells respond to two or more basic tastes

brain distinguishes them reliably

Question 8

T/F: Taste receptors are neurons.

Answer 8

false; however they do form synapses with the endings of the gustatory afferent axons near the bottom of the taste bud

Question 9

What is the cell cycle of taste buds?

Answer 9

2 weeks

Question 10

Activation is usually through […]: an opening/influx of […] and then […] molecules that excite […] that fires an AP.

Answer 10

receptor potential; Ca2+; release of NT; postsynaptic sensory axon

Question 11

Each cell can be affected by different tastes, however, there are some biases that is dependent on […].

Answer 11

taste transduction

Question 12

Transduction:

Answer 12

process by which an environmental stimulus causes an electrical response in a sensory receptor