Lecture 36 - Chemical senses Flashcards Preview

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Flashcards in Lecture 36 - Chemical senses Deck (66):
0

What two things does flavor perception drive?

Olfactory, taste, and somatosensory cues

1

Where is the olfactory mucosa?

Roof of the nasal cavity

2

What is within the olfactory mucosa?

Mucus layer with odorant-binding proteins, olfactory, epithelium, underlying basal lamina (Bowman's gland)

3

What is mucus secreted from in the olfactory mucosa?

Supporting cells
-- and --
Bowman's gland

4

What cell types are within the olfactory epithelium?

Olfactory receptor neurons
Supporting/sustentacular cells
Basal cells

5

What is the function of the basal cells in the olfactory epithelium?

Stem cells; give rise to new receptors

6

What is the lifespan of the olfactory receptors?

30-60 days

7

What is the function of the supporting cells in the olfactory epithelium?

Columnar cells - contribute to mucus production

8

What kind of neuron are the olfactory receptor neurons?

Bipolar neurons

9

What are the two regions of the olfactory bipolar neurons?

Apical dendrite
-- and --
basal unmyelinated axon

10

What is occurring at the dendritic end of the olfactory neurons?

Terminates in the olfactory vesicle
Protrude into the mucous layer and contain receptors

11

What happens at the basal end of the olfactory receptors?

Projects through the Cribriform plate with other axons as bundles (Olfactory fila)

12

What does the basal end of the olfactory receptor neurons synapse on?

Glomeruli of the olfactory bulb

13

How do the odorants in the air reach the olfactory receptor?

Cross the mucosa via binding to odorant binding proteins

14

How many odorant receptors does each olfactory receptor get?

One

15

What are the two transduction mechanisms that occur in olfactory transduction?

One cation
-- and --
One calcium

16

What happens to the olfactory neuron when transduction occurs?

Depolarization

17

What is receptor cycling?

Once odorant receptor becomes saturated it retreats into the cell

18

What type of receptor is a olfactory receptor?

G-protein coupled

19

What type of system is the olfactory system? (in regards to how it works)

Change detector system - detects new odorants and ignores old ones

20

What is the central olfactory pathway? (basic)

Olfactory bulb - Tract - Cortex

21

How many layers are within the olfactory bulb?

5

22

What happens with the axons of the olfactory receptor?

Pass through the cribriform plate
Terminate in the olfactory bulb

23

What are the five layers of the olfactory bulb?

Olfactory nerve
Glomerular
External plexiform
Mitral cell
Granule cell

24

What is within the olfactory nerve layer?

AXONS of the olfactory receptor neurons

25

What is within the glomerular layer?

Synapses of olfactory receptor neurons on mitral and tufted cells
Periglomerular cells
Tonography of odors

26

What types of neurons are periglomerular cells?

Interneurons

27

How are glomerular synapses organized?

Each synapse receives same odorant information

28

What synapses on the glomeruli after the olfactory receptors?

Mitral cells

29

What is contained within the external plexiform layer?

Cell bodies of tufted cells

30

What is contained within the mitral layer?

Cell bodies of mitral cells

31

What are the three cell layers of the olfactory cortex?

Periamygdaloid - Piriform - Enorhinal

32

What is the path of olfactory information through the olfactory cortex?

anterior olfactory nucleus
olfactory tubercle
piriform cortex
amygdala
periamygdaloid cortex
entorhinal cortex

33

What is the main output for the association fiber system?

Lateral hypothalamus

34

What are other, besides lateral hippocampus, regions that the association fiber system projects to?

Ipsilateral olfactory bulb
Contralateral olfactory bulb/cortex
Hippocampus

35

What projects to the hipocampus?

Lateral entorhinal cortex

36

What does the anterior olfactory nucleus project to?

Ipislateral/Contralateral olfactory bulb

37

What is important for feeding behavior?

Olfactory cortex projecting to the lateral hypothalamus

38

What is important for learning behavior?

Entorhinal cortex neurons projecting to the hippocampus

39

What is responsible for odor discrimination and identification?

Orbitofrontal cortex and insula

40

What also goes to the Orbitofrontal and insula?

Taste input

41

What is disosmia?

Reduction/loss of sense of smell

42

What are three things that can cause disosmia?

Mucosal
Obstruction
Nerve/brain

43

What is the function of the vomeronasal organ?

Sexual activity - Flehman reaction - Emotional states - Illnesses

44

What are the three types of papillae on the tongue?

Vallate - Foliate - Fungiform

45

What part of the tongue do fungiform papillae cover?

Anterior 2/3

46

What part of the tongue does the vallate papillae cover?

8-12 in V-shape on posterior tongue

47

Where are the foliate papillae?

one on each side of lateral tongue

48

What are the characteristics of a supertaster?

Higher density of fungiform papillae
Experience greater oral burn and oral touch
Supersniffers as well

49

Where are taste buds located?

Tongue papillae

50

What is the structure of a taste bud?

Taste pore - opening
Innervated by afferent neurons

51

What is the lifespan of a taste bud?

10-14 days

52

What part of the taste bud does the supporting cell make/

The outside portion

53

How many taste receptors to a taste bud?

40-60

54

What is the apical end of the taste bud covered in?

Microvilli

55

How does salty transduction occur?

Sodium of salt taste molecules may eneter through cation channels

56

What does sour transduction occur?

Protons of the sour taste molecules may block potassium channels

57

How is sweet, bitter, and sour tasted?

G protein coupled receptors

58

What is the central taste pathway for the anterior 2/3 of the tongue?

Fungiform/Foliate papillae - taste afferents - chorda tympani of facial nerve - geniculate ganglion - ipsilateral rostral solitary nucleus

59

What is the central taste pathway of the posterior 1/3 of the tongue?

Vallate papillae/Foliate papillae - taste afferent neurons - glossopharyngeal n. - Inferior ganglion of CN IX - ipsilateral rostral solitary tract

60

What is the central pathway for the soft palate?

Extralingual taste buds - taste afferent neurons - greater petrosal branch of the Facial N. - Geniculate ganglion - Ipsilateral rostral solitary nucleus

61

What is the central taste pathway for the epiglottis/esophagus?

Extralingual taste buds - taste afferent neurons - superior laryngeal br. of vagus n. - inferior ganglion of CN X - ipsilateral rostral solitary nucleus

62

What are the three ganglia involved with taste?

Geniculate - Petrosal - Nodose

63

What CN is the geniculate n. related to?

Facial n.

64

What CN is the petrosal ganglia related to?

CN IX - Glossopharyngeal

65

What CN is the nodose ganglia related to?

Vagus n.