The Chemical Senses: Taste and Smell

Question 1

What are the 5 primary senses?

Answer 1

Salty, sour, sweet, bitter and umami

Question 2

What taste is triggered by Na+ electrolyte balance?>

Answer 2

Salty

Question 3

What is triggered by H+?

Answer 3

Sour - unripe or rotten food

Question 4

What is triggered by certain organic molecules that are energy sources?

Answer 4

Sweet

Question 5

What is triggered by a variety of very different substances ranging from Mg2+ to complex molecules such as denatonium?

Answer 5

Bitter - toxic or poisonous substances

Question 6

What is triggered by glutamate and aspartate?

Answer 6

Umami - amino acid containing food

Question 7

Type I cells have glial-like properties and may buffer [K+] around taste receptor cells and transduce _______ taste. They have epithelial sodium channels as well.

Answer 7

Salty

Question 8

Type II cells possess G-protein coupled receptors and release ATP via voltage-gated channels to excite afferent nerves. What tastes do type II cells transduce?

Answer 8

Sweet, bitter, or umami

Question 9

Type II cells are also called presynaptic cells becuase of their prominent synapses with sensory nerve fibers. These cells release ________ and _______________ onto afferent nerves.

Answer 9

Serotonin and norepinephrine

Question 10

What taste do type III cells transduce?

Answer 10

Sour

Question 11

How many taste receptor cells does each taste bud contain?

Answer 11

50-140

Question 12

Each taste bud has a small opening on the epithelial surface called a ________________.

Answer 12

Taste pore

Question 13

T/F - Each TRC responds to multiple tastants.

Answer 13

False - only one tastant per TRC

Question 14

What type of junctions join taste receptor cells?

Answer 14

Tight junctions

Question 15

How often are TRCs turned over?

Answer 15

Once every 3 weeks

Question 16

Taste buds of the tongue are located in the __________.

Answer 16

papillae

Question 17

What papillae are located on the anterior 2/3 of the tongue?

Answer 17

Fungiform

Question 18

What papillae have peg-like structures?

Answer 18

Fungiform

Question 19

What type of papillae contain about 50% of the taste buds of the oral cavity?

Answer 19

Fungiform

Question 20

The fungiform papillae are innervated by the chorda tympani of the _____ nerve.

Answer 20

Facial (VII)

Question 21

What type of papillae are located on the posterior 1/3 of the tongue?

Answer 21

Circumvallate papillae

Question 22

What type of papillae contain 30% of the taste buds of the oral cavity and are semicircular, trench-like structures?

Answer 22

Circumvallate papillae

Question 23

Circumvallate papillae are innervated by the _______________________ nerve.

Answer 23

Glossopharyngeal (IX) nerve.

Question 24

_______________ papillae are located on the posterior, lateral border of the tongue.

Answer 24

Foliate

Question 25

Foliate papillae contain about ___% of the taste buds of the oral cavity.

Answer 25

15%

Question 26

Foliate papillae are innervated by _____________________________ nerve.

Answer 26

Glossopharyngeal (IX) nerve

Question 27

The taste buds of the palate are innervated by the _____ nerve.

Answer 27

Facial (VII)

Question 28

The pharynx, epiglottis, and upper esophagus taste buds are innervated by the _____________ nerve.

Answer 28

Vagus (X)