Exam #6: Taste & Olfaction

Question 1

List the five primary sensations of taste.

Answer 1

Sour 
Salty 
Sweet 
Bitter
Umami

Question 2

What substances elicit sour taste?

Answer 2

Acids e.g. HCl

Question 3

What substances elicit salty taste?

Answer 3

Ionized salts i.e. NaCl

Question 4

What substances elicit sweet taste?

Answer 4

Sugars
Glycols (poisoning)
Alcohols
Amino acids

Question 5

What substances elicit bitter taste?

Answer 5

Alkaloids
Caffeine
Nicotine

Question 6

What substances elicit umami taste?

Answer 6

MSG
Glutamate
Amino acids

*Meat & cheese

Question 7

What cranial nerves are involved in transmitting taste information?

Answer 7

CN VII
CN IX
CN X

Question 8

Which cranial nerve innervates the anterior 2/3 of the tongue?

Answer 8

CN VII

Question 9

Which CN innervates the back of the tongue?

Answer 9

CN IX

Question 10

Which CN innervates the soft palate, the epiglottis and esophagus?

Answer 10

Soft palate= CN VII

Epiglottis & esophagus= CN X

Question 11

How do we classify taste receptor cells? Is it a neuron?

Answer 11

Taste buds are specialized sensory receptor for taste transduction

Question 12

How do we classify olfactory receptor cells? is it a neuron?

Answer 12

Olfactory receptors are bipolar neurons

Question 13

What is the average life span of taste receptor cells? How does this compare to olfactory neurons?

Answer 13

Taste= 10 days- 2 weeks 
Olfactory= ~60 days

Question 14

What is the biological role of taste?

Answer 14

• Protection–bitter substances can stimulate protrusion of the tongue and gag
• Edibility
• Diet selection
• Taste aversion

Question 15

What is the biological role of olfaction?

Answer 15

• Combine with taste to get gustatory sensation

- Pharamones for sex

Question 16

What is bait-shyness?

Answer 16

If an animal feels sick after eating, assumption is that the novel food is responsible–animal will lose taste for the food

Question 17

What is the clinical significance of bait-shyness?

Answer 17

This is how we lose a taste for something that has been perceived to make us sick

Question 18

What is hyposmia?

Answer 18

Decrease sense of smell

Question 19

What is anosmia?

Answer 19

No sense of smell

Question 20

What is parosmia?

Answer 20

Perversion of the sense of smell

Question 21

What is hypogeusia?

Answer 21

Less taste sensation

Question 22

What is ageusia?

Answer 22

No taste sensation

Question 23

What is parageusia?

Answer 23

Perversion of the sense of taste i.e. a bad taste in the mouth

Question 24

Outline the afferent pathway of taste information.

Answer 24

1) CN
2) NTS
3) VPM of the Thalamus
4) Insular & frontal taste cortices