Lecture 41: Neuroanatomy of the Chemical Senses

Question 1

What are supporting or sustentacular cells

Answer 1

Columnar cells which contribute to mucus

Question 2

What are basal cells in olfactory epithelium

Answer 2

Stem cells which give rise to new olfactory neurons with lifespan of 30-60 days

Question 3

What are the apical dendrites

Answer 3

Dendrites that terminate in the olfactory vesicle with 10-30 no motile cilia that produce into mucus layer and contain odorant receptors

Question 4

What axons project through cribs form plate with other axons as bundles called olfactory fila that synapse in the glomeruli of the olfactory bulb

Answer 4

Basal unmyelinated axons

Question 5

Air is exhaled through ___so it doesn’t dilute the scent of incoming air

Answer 5

Side slits

Question 6

Olfactory transduction uses what kind of receptors

Answer 6

GPCR

Question 7

Odorant molecules interact with what proteins to cross mucus layer

Answer 7

Odorant binding proteins

Question 8

Only one type of odorant receptor per ____ neuron

Answer 8

Olfactory receptor neuron

Question 9

Odorant molecules bind to odorant receptors on ___ of olfactory receptor neurons where transduction occurs

Answer 9

Cilia

Question 10

What are the two transduction mechanisms for olfaction

Answer 10

Cation and calcium

(Both led to olfactory depolarization)

Question 11

T/F: odor compounds can combine to stimulate various odorant receptors with variable activations. Perceptions of smell rely on relative strength of activation combinations

Answer 11

T

Question 12

Explain why we get used to smells

Answer 12

Olfaction is a change detector system so when odorant receptors are saturated they will undergo receptor cycling and odorant molecule is unbound from receptor

Benefit is we filter out background odors to detect new ones

Question 13

What are the 5 layers of the olfactory bulb

Answer 13

1. Olfactory sensory neurons (olfactory epithelium)
2. Periglomerular cells (glomeruli)
3. Tufted cells (glomeruli)
4. Mitral cells (olfactory bulb)
5. Granule cells (olfactory bulb)

Question 14

Each glomerulus synapses with olfactory neurons that all produce the ___type of odorant receptor

Answer 14

Same

Question 15

CN I carries olfactory information back to what part of the brain

Answer 15

Piriform lobe

Question 16

What part of cortex receives olfaction

Answer 16

Olfactory cortex

Question 17

What part of cortex receives olfaction and taste

Answer 17

Orbitofrontal

Question 18

What part of cortex receives taste

Answer 18

Insula

Question 19

Olfactory neurons that project to ____ affect feeding behavior and appetite

Answer 19

Hypothalamus

Question 20

Entorhinal cortex neurons that project to ___ affect learning and learned repsonses

Answer 20

Hippocampus

Question 21

Amygdala projections contribute to ___responses

Answer 21

Emotion

Question 22

What organ is involved in sexual activity, particular the lip curl reaction demonstrated by male animals aroused by odor of vaginal secretion or urine from estrous females

Answer 22

Vomeronasal organ

Question 23

What are the 5 tastes

Answer 23

Sweet, sour, salty, bitter and umami

Question 24

T/F: specific taste buds are regionally located

Answer 24

False- all tastes buds are distributed across tongue

Question 25

What papillae are on the rostral 2/3 of tongue

Answer 25

Fungiform papillae

Question 26

What papillae are on caudal tongue

Answer 26

Vallate papillae

Question 27

Where are the foliate papillae located

Answer 27

1 on each side

Question 28

Taste buds are located on the ___

Answer 28

Tongue papillae

Question 29

T/F: taste buds are innervated by multiple neurons

Answer 29

T

Question 30

What cells form outer envelope of bud

Answer 30

Supporting cells

Question 31

What cells give rise to new taste receptor within 10-14 days

Answer 31

Basal stem cells

Question 32

What covers the end of each taste bud

Answer 32

Microvilli

Question 33

What tastes directly interact with specific ion channels to depolarize

Answer 33

Salty and sour

Question 34

What taste has their protons block potassium channels

Answer 34

Sour

Question 35

What tastes use GPCR’s to initiate depolarization

Answer 35

Sweet, sour, bitter

Question 36

What is the only taste penguins have

Answer 36

Salty, sour

Question 37

What tastes do cats lack

Answer 37

Sweet

Question 38

What are the three sensory taste nerves

Answer 38

1. Chorda tympani (VII) 2. Glosspharyngeal (IX) 3. Vagus (X)

Question 39

What nerve provides taste to epiglottis

Answer 39

Vagus

Question 40

What nerve provides taste to caudal 1/3 of tongue

Answer 40

Glossopharyngeal

Question 41

What nerve provides taste to rostral 2/3 of tongue

Answer 41

Chorda tympani

Question 42

All taste sensations from VII, IX and V are transmitted to ___ nucleus and tract in ____

Answer 42

Solitary nucleus and tract in brainstem