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Flashcards in Taste buds and stuf Deck (50):
1

What part of the tongue has specialized mucosa?

Dorsal

2

Body of the tongue

Anterior 2/3

3

Root of the tongue

Posterior 1/3

4

Terminal sulcus

Divides the anterior and posterior portions of the tongue

5

What type of epithelium covers the tongue

Mostly keratinized

6

What give the tongue its rough surface?

Papillae

7

What CN inneervate the taste buds?

VII, IX, X

8

What provides touch sensory to the tongue?

A-beta fibers

9

What innervates warming sensation of the tongue

C-fibers

10

What innervates cooling sensation of the tongue?

A-delta fibers

11

What provides pain sensation of the tongue

A-delta and C-fibers

12

What provides somatosensory innervations of the anterior tongue?

CN V

13

What provides somatosensory innervation to the posterior of the tongue

CN IX

14

Meissner Corpuscles

Large (A-beta) axons that terminate in the superficial lamina propria between rete pegs

15

Which nerves are "rapidly adapting"? what does that mean?

Meissner Corpuscles
Respond only to the changing aspects of the stimulus - mechanically sensitive receptors are embedded in the nerve fiber endings

16

Which nerves are "slowly adapting"? What does that mean?

Merkel endings
Respond both to the changing aspects and static phases of stimulus

17

In Merkel endings, where does the initial firing come form, and where does the continued firing come form?

Initial firing comes from activation of the receptors in the nerve fiber itself
Sustained firing comes from activation of receptors in the Merkel cell which communicates synaptically with the associated fiber

18

Nocioceptors

Free nerve endings that sense pain
Merkel endings and Meissner corpuscles can't code for nosxious sensations

19

What are some things taste can detect/distinguish?

Can distinguish nutritive v non-nutritive substances
Can distinguish nutrients
Can detect harmful substances

20

What are the 5 classes of taste reception?

Sugars - sweet
Amino acids - umami
Salts - salty
Acids - sour
Varied - bitter

21

T/F - Sensations of spiciness is dependent of taste system

False - dependent on the pain system - TRP receptors

22

How many cells in a taste bud? How are these cells oriented

40-60
90 degrees to the rest of the epithelium

23

What cellular structure are taste receptors located?

Microvilli

24

Taste pore

Opening to keratinized layer to let things diffuse and be sensed by microvilli
Lateral to the microvilli

25

T/F - Taste buds are only on the tongue

False - they are mostly on the tongue, but there are some in the pharynx and soft palate

26

Fungiform papillae shape

Mushroom shaped

27

What innervates fungiform papillae?

Chorda tympani branch of VII
-They arise from arch I, but the innervation arises from arch II

28

Where are fungiform papillae located?

On the dorsal anterior tongue, among more numerous filliform papillae

29

Filiform papillae

Spine shaped
Heavily keratinized
Do not contain taste buds
Innervated by sommatosensory only

30

Foliate papillae location. Why is it strategic?

Lateral aspect of the posterior portion of the anterior tongue
Monitor food during chewing

31

Where are taste buds located of foliate papillae?

In the trenches

32

Where are taste buds of fungiform papillae located?

On the top

33

Foliate papillae

2-9 parallel folds in dorsoventral orientation
Closely associated with Von Ebners glands

34

Circumvallate papilae

8-10 papillae arranged in a V in the most posterior anterior tongue

35

What is the structure of circumvallate papillae?

Central connective tissue core surrounded by a trench

36

Why is the location of circumvallate papillae strategic?

Monitor food just before swallowing

37

Where are tastebuds located in Circumvallate papillae?

In the trench

38

What happens when a single taste nerve is damaged?

The effects of that single taste nerve an be clearly detected. However, when that person is allowed to use all the taste buds in their mouth, the effects are very minor

39

Type I cells

Stain for glial markers and don't have microglia or synapses.
This suggests that these cells are likely for support

40

Dark staining taste bud cells

Type I cells

41

Light staining taste bud cells

Type II cells
Type III cells

42

Type III cells

Sour
Synapse with primary afferent nerve
Have microvilli

43

Type II cells

Bitter, sweet, amino acids
Do not synapse with primary afferent nerve
Have microvilli

44

How do type II cells get their messages to the brain?

ATP is released from type II cells without the aid of a typical synapse, and uses a special voltage-gated ion channel

45

What signaling molecule do precursor taste buds cells express?

Shh

46

How do taste buds develop?

First develops as a specialization of epithlium called a 'placode'
Development requires cell-to-cell signaling
Final differentiation requires neural innervation

47

When does the tongue appear?

Week 4 IU

48

When do the lingual papillae develop?

Week 8 IU

49

When do taste buds first appear?

Week 8 IU

50

When do taste pores appear?

Week 12 IU