EX3; Oral Mucosa Sensations

Question 1

What are the three parts of the dorsal tongue

Answer 1

root
body
terminal sulcu

Question 2

Where are the root and the body of the tongue derived from

Answer 2

body = mucosa from branchial arch 1
root = mucosa from branchial arch 3

Question 3

What kind of keratinization of the epithelium is located on the dorsal tongue

Answer 3

most keratinized except for in a few key locations

Question 4

What kind of lamina propria does the dorsal tongue contain

Answer 4

flexible; other side is more rigid

Question 5

True or False

The dorsal tongue does not contain a submucosa

Answer 5

True

Question 6

The dorsal tongue contains numerous papillae, what different kinds

Answer 6

some papillae are taste buds

some papillae are innervated by somatosensory nerve endings

Question 7

True or False

Sensation is only registered from the tongue

Answer 7

False; it is in the mucosa as well

Question 8

What cranial nerves supply taste to the taste buds

Answer 8

facial - VII
glossopharyngeal - IX
vagus - X

Question 9

This cranial nerve supplies the anterior mouth

Answer 9

trigemial - V

Question 10

This cranial nerve supplies the posterior tongue and pharync

Answer 10

glossopharyngeal - IX

Question 11

These fibers supply a touch sensation

Answer 11

A beta

A delta

Question 12

These fibers supply a warming sensation

Answer 12

C fibers

Question 13

These fibers supply a cooling sensation

Answer 13

A delta

Question 14

These fibers supply a painful sensation

Answer 14

A delta

C fibers

Question 15

This somatosensory receptor is associated with large axons (A beta) and terminates in the superficial lamina propria between the rete pegs

Answer 15

Meissner’s corpuscles

Question 16

What kind of forces are associated with Meissner’s corpuscles

Answer 16

dynamic forces; rapidly adapting

Question 17

This somatosensory receptor is associated with large axons (A beta) and terminus at the apices of the tete pegs

Answer 17

Merkel receptors

Question 18

What kind of forces are associated with Merkel receptors

Answer 18

static forces; slowing adapting

Question 19

This somatosensory receptor complexes of nerve endings and specialized epithelial cells

Answer 19

Merkel receptors

Question 20

This somatosensory receptor complexes of nerve endings encapsulated by non-nueronal cells

Answer 20

Meissner’s corpuscles

Question 21

What kind of threshold do both Merkel and Meissner’s receptors have

Answer 21

very low threshold; very sensitive

Question 22

True or False

Merkel’s receptors only respond during static forces

Answer 22

False; they also respond during dynamic, but also (and solely) during static, Meissner’s does not respond during static

Question 23

True or false

Merkel and Meissner’s receptors code painful senstations

Answer 23

False; they do not because their dynamic range does not extend to the noxious (harmful) range

Question 24

What is used to transmit painful sensations

Answer 24

nociceptors
free nerve endings
A delta and C fibers

Question 25

What are the main functions of the taste system

Answer 25

detect chemicals in the food distinguish between nutritive/non-nutritive detect harmful substances

Question 26

What are the 5 classes of taste receptors that detect the 5 classes of stimuli

Answer 26

``` sugars (sweet) amino acids (umami) salts (salty) acids (sour) varied alkaloid, purines, glycosides (bitter) ```

Question 27

This is goblet shaped closed of 40-60 cells at right angles to the basal lamina extending to the surface containing microvili and a taste pore

Answer 27

taste bud

Question 28

True or False | There are no nerve fibers at the base of taste buds

Answer 28

False; there are primary afferent fibers at the base and some bud cells synapse with these fibers

Question 29

How may taste buds are distributed in the mouth

Answer 29

around 8,000

Question 30

Where are the taste buds located

Answer 30

68% on the tongue 27% on pharynx/larynx 5% on soft palate

Question 31

These papillae around on the dorsal anterior tongue and contain around 1600 taste buds

Answer 31

fungiform papillae

Question 32

Where are the fungiform papillae derived from and what are the innervated by

Answer 32

branchial arch 1 | innervation = chorda tympani (BA2)

Question 33

Where are the fungiform papillae most numerous

Answer 33

at the tip of the tongue; they are located there to monitor food entering the mouth

Question 34

What is the shape of the fungiform papillae

Answer 34

mushroom shaped

Question 35

Where is the keratin layer interrupted regarding fungiform papillae

Answer 35

at the pore and between filliform papillae

Question 36

The fungiform papillae are located amongst what

Answer 36

filiform papillae

Question 37

Where are the taste buds located on the fungiform papillae

Answer 37

on the dorsal surface

Question 38

How many taste buds do each fungiform papillae typically have

Answer 38

around 3

Question 39

These are heavily keratinized spine shaped papillae which do not contain taste buds

Answer 39

filiform papillae

Question 40

What are filiform papillae innervated by

Answer 40

somatosensory fibers

Question 41

These are 2-9 parallel folds, dorsoventral orientation on the lateral aspect of the most posterior anterior tongue; strategic location to monitor food during chewing

Answer 41

foliate papillae

Question 42

How many taste buds are located on the foliate papillae and what are they innervated by

Answer 42

around 1300 taste buds | innervated by glossopharyngeal (BA3)

Question 43

Where are the taste buds of the foliate papillae and circumvallate papillae located

Answer 43

in the trenches; not on the surfaces

Question 44

What are the foliate papillae and circumvallate papillae closely associated with

Answer 44

salivary glands | specifically Von Ebner glands

Question 45

These are 8-10 papillae arranged in a "V" on the most posterior anterior tongue with a central connective tissue core surrounded by a trench used to monitor food just before swallowing

Answer 45

circumvallate papillae

Question 46

How many taste buds are on the circumvallate papillae

Answer 46

around 2400; densely packed

Question 47

Though the different taste papillae are distinctively histologically and innervated by different nerves, they are generally functionally redundant in their ability to do what

Answer 47

sense different tastes

Question 48

The taste buds on the larynx (epiglottis) respond to deviations in this, indicated the signal to protect the airway

Answer 48

isotonicity; response to water

Question 49

True or False | A single fungiform papillae can only detect one specific taste

Answer 49

False; they can usually detect more than one quality (~3 buds/papillae)

Question 50

What is important to know about the functional redundancy of the taste system

Answer 50

it makes it resilient to the face of partial taste loss

Question 51

When the chorda tympani is numbed, which side are the taste stimuli undetectable

Answer 51

on the ipsilateral side to the anesthesia

Question 52

What occurred involving the taste when both of the chord tympani's were numbed

Answer 52

there was no obvious taste loss

Question 53

True or False | The number of taste papillae varies greatly between individuals

Answer 53

True; women tend to have more then men

Question 54

True or False | The number of taste papillae dramatically decreases with age

Answer 54

False; it may only decrease slightly but mainly due to lost of olfactory sensations

Question 55

Fox accidentally discovered marked individual differences in the ability to taste what and the bimodal distribution of thresholds indicated this

Answer 55

``` bitter phenylthiocarbamide (PTC) it is an inherited trait ```

Question 56

In the last how many years was the functional characterization of receptors understood

Answer 56

in the last 15 years | 2000-2009

Question 57

This is a 30 member family of G-protein coupled bitter receptors of which each has a limited range for bitter compounds

Answer 57

tas2r

Question 58

What is largely responsible for the sensitivity differences to bitterness (PTC) in tas2r receptors

Answer 58

amino acid substitutions

Question 59

Vegetables containing this compound are significantly more bitter to people who are homozygous for PTC sensitive tas2r

Answer 59

glucosinolates

Question 60

True or False | People with more sweet receptors prefer lesser sweet things

Answer 60

True; | people with less sweet receptors prefer more sweet things, this can contribute to caries production

Question 61

True or False | both genetic and environmental factors contribute to individual taste sensitivity and preference

Answer 61

True

Question 62

These cells of a taste bud are on the lateral aspect, in the epithelium at right angles to the basal lamina, contain microvili, and do not synapse

Answer 62

perigemmal cells

Question 63

What is the presumed function of perigemmal cells

Answer 63

support or renewal

Question 64

These cells are located at the base of the taste bud, in the epithelial basal cells, and their function is renewal

Answer 64

basal cells

Question 65

These cells are at the center of the taste bud and have receptors that convey stimulus

Answer 65

elongated cells

Question 66

This type of elongated cell stains for glial markers suggesting a supportive role; it also may respond to salts, and there are no synapses

Answer 66

Type 1 (dark)

Question 67

This type of elongated cell expresses receptors for taste substances and responds to taste stimuli; there are two types

Answer 67

light cells

Question 68

This type of light cell responds to sour taste and synapses with primary afferent nerves

Answer 68

Type III

Question 69

This type of light cell responds to bitter, sweet, and amino acid tastes and does not synapse with primary afferent nerves

Answer 69

type II

Question 70

Type II and type III use this to communicate with the primary afferent taste nerves; in regards to type II, it is the primary transmitter

Answer 70

ATP

Question 71

K19 (keratin) is expressed during what, and this indicates what

Answer 71

expressed during development and reflects the rapid turnover of taste receptor cells

Question 72

In which embryological week does the taste buds first appear

Answer 72

week 8

Question 73

In which embryological week does the taste pores first appear

Answer 73

week 12

Question 74

What has been indicated about taste preferences in infants

Answer 74

the basic taste system is hard wired at birth (facial expressions upon bitter/sweet) but the natural taste preferences are altered by experience (enfamil and nutramigen formulas)