Chemosensation

Question 1

Sweet, bitter, and umami tastes are transmitted via _____ receptors.

Answer 1

metabotropic GPCRs

Question 2

What is the receptor cell for chemmesthesis? What CN does it use?

Answer 2

• free nerve ending of cranial ganglion cells
• CN 5

Question 3

Where is the primary sensory nucleus in the CNS for olfaction?

Answer 3

olfactory bulb

Question 4

This is the term for the loss of taste.

Answer 4

Ageusia

Question 5

Parosmia

Answer 5

Altered perception of smell in the presence of an odor, usually unpleasant

Question 6

How are the neural pathways different for taste and smell?

Answer 6

taste has to go thru the thalamus, but smell does not

Question 7

In taste, where do the thalamic neurons send their axons?

Answer 7

to the insular cortex

Question 8

This is an altered perception of smell in the presence of an odor; usually unpleasant .

Answer 8

Parosmia

Question 9

Salty and sour tastes are transmitted via _____ receptors.

Answer 9

ion channels

Question 10

Hyposmia

Answer 10

diminished sense of smell

Question 11

Taste involves stimulation of what 3 sensory systems?

Answer 11

1. olfaction
2. gustation
3. chemesthesis

Question 12

What are the 2 routes that odorants take into the body?

Answer 12

• Ortho-nasal = through nostrils
• Retro-nasal = mouth –> through the concha –> olfactory epithelium

Question 13

Where are the 2nd order cells for taste?

Answer 13

medial part of the ventrobasal thalamus (VPMpc)

Question 14

This is an altered/distorted sense of smell.

Answer 14

dysosmia

Question 15

What is the receptor cell for taste? What CN does it use?

Answer 15

• a modified epi cell
• CN 7, 9, 10

Question 16

Anosmia

Answer 16

a sudden loss of smell

Question 17

What is the receptor cell for olfaction? What CN does it use?

Answer 17

• a cilitated, bipolar neuron
• CN1

Question 18

Where is the primary sensory nucleus in the CNS for chemesthesis?

Answer 18

spinal trigeminal nucleus

Question 19

What is the term for the diminished sense of smell?

Answer 19

hyposmia

Question 20

Dysosmia

Answer 20

altered/distorted sense of smell

Question 21

What is the significance of the Entorhinal cortex?

Answer 21

feeds into hippocampus –> storage and retrieval of memories

Question 22

Olfactory axons project directly onto the ______.

Answer 22

• olfactory cortex
• a portion of the amygdala

Question 23

A sudden loss of smell is called?

Answer 23

anosmia

Question 24

What part of the brain gives conscious appreciation of smell?

Answer 24

the Orbitofrontal cortex

Question 25

Ageusia

Answer 25

loss of taste

Question 26

Anosmia can often lead to ____.

Answer 26

severe depression

Question 27

Phantosmia

Answer 27

Perception of smell without an odor present

Question 28

What are the 3 kinds of taste papillae? Where are they found? What CN innervates them?

Answer 28

1. fungiform (anterior): facial- 7
2. foliate (sides): facial - 7
3. circumvallate (posterior): glossopharyngeal - 9

Question 29

This is the perception of smell without an odor present.

Answer 29

Phantosmia

Question 30

Where is the primary sensory nucleus in the CNS for taste?

Answer 30

nucleus of solitary tract