Taste buds and stuf

Question 1

What part of the tongue has specialized mucosa?

Answer 1

Dorsal

Question 2

Body of the tongue

Answer 2

Anterior 2/3

Question 3

Root of the tongue

Answer 3

Posterior 1/3

Question 4

Terminal sulcus

Answer 4

Divides the anterior and posterior portions of the tongue

Question 5

What type of epithelium covers the tongue

Answer 5

Mostly keratinized

Question 6

What give the tongue its rough surface?

Answer 6

Papillae

Question 7

What CN inneervate the taste buds?

Answer 7

VII, IX, X

Question 8

What provides touch sensory to the tongue?

Answer 8

A-beta fibers

Question 9

What innervates warming sensation of the tongue

Answer 9

C-fibers

Question 10

What innervates cooling sensation of the tongue?

Answer 10

A-delta fibers

Question 11

What provides pain sensation of the tongue

Answer 11

A-delta and C-fibers

Question 12

What provides somatosensory innervations of the anterior tongue?

Answer 12

CN V

Question 13

What provides somatosensory innervation to the posterior of the tongue

Answer 13

CN IX

Question 14

Meissner Corpuscles

Answer 14

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

Question 15

Which nerves are “rapidly adapting”? what does that mean?

Answer 15

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

Question 16

Which nerves are “slowly adapting”? What does that mean?

Answer 16

Merkel endings

Respond both to the changing aspects and static phases of stimulus

Question 17

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

Answer 17

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

Question 18

Nocioceptors

Answer 18

Free nerve endings that sense pain

Merkel endings and Meissner corpuscles can’t code for nosxious sensations

Question 19

What are some things taste can detect/distinguish?

Answer 19

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

Question 20

What are the 5 classes of taste reception?

Answer 20

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

Question 21

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

Answer 21

False - dependent on the pain system - TRP receptors

Question 22

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

Answer 22

40-60

90 degrees to the rest of the epithelium

Question 23

What cellular structure are taste receptors located?

Answer 23

Microvilli

Question 24

Taste pore

Answer 24

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

Question 25

T/F - Taste buds are only on the tongue

Answer 25

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

Question 26

Fungiform papillae shape

Answer 26

Mushroom shaped

Question 27

What innervates fungiform papillae?

Answer 27

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

Question 28

Where are fungiform papillae located?

Answer 28

On the dorsal anterior tongue, among more numerous filliform papillae

Question 29

Filiform papillae

Answer 29

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

Question 30

Foliate papillae location. Why is it strategic?

Answer 30

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

Question 31

Where are taste buds located of foliate papillae?

Answer 31

In the trenches

Question 32

Where are taste buds of fungiform papillae located?

Answer 32

On the top

Question 33

Foliate papillae

Answer 33

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

Question 34

Circumvallate papilae

Answer 34

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

Question 35

What is the structure of circumvallate papillae?

Answer 35

Central connective tissue core surrounded by a trench

Question 36

Why is the location of circumvallate papillae strategic?

Answer 36

Monitor food just before swallowing

Question 37

Where are tastebuds located in Circumvallate papillae?

Answer 37

In the trench

Question 38

What happens when a single taste nerve is damaged?

Answer 38

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

Question 39

Type I cells

Answer 39

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

Question 40

Dark staining taste bud cells

Answer 40

Type I cells

Question 41

Light staining taste bud cells

Answer 41

Type II cells | Type III cells

Question 42

Type III cells

Answer 42

Sour Synapse with primary afferent nerve Have microvilli

Question 43

Type II cells

Answer 43

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

Question 44

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

Answer 44

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

Question 45

What signaling molecule do precursor taste buds cells express?

Answer 45

Shh

Question 46

How do taste buds develop?

Answer 46

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

Question 47

When does the tongue appear?

Answer 47

Week 4 IU

Question 48

When do the lingual papillae develop?

Answer 48

Week 8 IU

Question 49

When do taste buds first appear?

Answer 49

Week 8 IU

Question 50

When do taste pores appear?

Answer 50

Week 12 IU