An overview of the oral mucosa

Question 1

what structures are included in the oral mucosa

Answer 1

upper lip 
alveolar mucosa 
hard palate 
soft palate 
cheek 
dorsal surface of the tongue 
gingiva 
floor of mouth
lower lip

Question 2

what is the oral mucosa

Answer 2

the moist lining that covers the whole of the oral cavity

Question 3

what are the differences between the oral mucosa and skin

Answer 3

the colour- oral mucosa lighter- the skin has keratin which is thicker and doesn’t allow blood vessels to show through as much
moisture- oral mucosa has a constant moist surface due to secretion of saliva
appendages- mucosa doesn’t have hair follicles sweat and sebaceous glands

Question 4

what mechanical challenges does the oral mucosa face

Answer 4

chewing

Question 5

what are the functions of the oral mucosa

Answer 5

protection 
sensation 
secretion 
absorption 
thermal regulation( in dogs) not humans

Question 6

what does saliva contain

Answer 6

antimicrobial peptides which help battle invading microbes that enter

Question 7

what does the oral mucosa protect against

Answer 7

mechanical
abrasive
microbial threats

Question 8

what sensations can be felt in the oral mucosa

Answer 8

touch
temperature
taste
thirst and pain

Question 9

what can be absorbed in the oral mucosa

Answer 9

sublingual dissolving drugs

Question 10

what function occurs in dogs but not humans

Answer 10

thermal regulation- as dogs pant when they are too hot

Question 11

what drug is used sublingually during angina attacks

Answer 11

GTN spray- glyceryl trinitrite spray 3x sprays sublingually

Question 12

what re the types of oral mucosa

Answer 12

masticatory mucosa
lining mucosa
specialised mucosa

Question 13

describe masticatory mucosa

Answer 13

areas that are subject to more mastication

more highly keratinised

Question 14

describe lining mucosa

Answer 14

lines areas that are less subject to masticatory forces and the surface of these is less keratinised

Question 15

describe specialised mucosa

Answer 15

subject to masticatory forces so has some keratin but has specialised tissue and structures related to taste eg the upper surface of the tongue

Question 16

where is masticatory mucosa found

Answer 16

on the surface of the gingiva
hard palette
stiffer tissues

Question 17

where can the lining mucosa be found

Answer 17

on the vermillion border 
the lining of the cheek 
lining of the lips 
floor of the mouth
ventral surface of the tongue

Question 18

when might the lining mucosa suffer from masticatory forces

Answer 18

due to malocclusion

Question 19

what are the different types of papilla from anterior to posterior of the tongue

Answer 19

filiform papilla
fungiform papilla
circumvallate papilla
foliate papilla

Question 20

describe the anterior 2/3 rds of the tongue

Answer 20

keratinised mucosa with specialised structures called papilla which hold tastebuds

Question 21

describer the posterior 1/3 rd of the tongue

Answer 21

filled with lymphoid tissue and called the lingual tonsil

Question 22

what is the main tissue component of the oral mucosa

Answer 22

epithelium 
lamina propia 
submucosa 
periosteum
bone

Question 23

what two parts make up connective tissue

Answer 23

lamina propia

submucosa

Question 24

what is epithelial tissue

Answer 24

can be formed from ectoderm mesoderm or endoderm- closely packed layer of cells which line a cavity or hollow organ or body surface

Question 25

what are the types of epithelial tissue

Answer 25

``` simple squamous simple cuboidal simple columnar transitional pseudo stratified columnar stratified cuboidal stratified squamous ```

Question 26

what are the two major types of epithelial cells

Answer 26

simple cells- one layer of cells | stratified cells- multilayer of cells

Question 27

what cells is the oral mucosa covered by

Answer 27

stratified squamous epithelium

Question 28

what are the types of attachments between cells

Answer 28

``` tight junctions adherens junctions gap junction hemidesmosomes desmosomes ```

Question 29

what is the desmosome

Answer 29

thickening plaques of the cell membrane which contains transmembrane filaments which contains cadherin protein

Question 30

what protein is found in desmosomes

Answer 30

cadherin

Question 31

describer the tight junction

Answer 31

specialised protein structure and tightens the gap between cells and prevents leakage and has selective permeable functions hold adjacent epithelial structures together

Question 32

describe the hemidesmosome

Answer 32

thickening plaques of the cell membrane which contains transmembrane filaments allows the cells to be tightly attached to the underlying basal lamina membrane and the ECM

Question 33

what is the difference between keratinised and non keratinised

Answer 33

keratinsed- doesn't look like cells as it is a protein and forms a thick layer on top of the cells non keratinised- thicker and formed of more layers of cells due to the fact has to resist masticatory forces

Question 34

what are the cellular components of the oral epithelium

Answer 34

keratinocytes and non keratinocytes

Question 35

describer keratinocytes

Answer 35

those cells of keratinised and non keratinised epithelium

Question 36

give examples of non keratinocytes

Answer 36

melanocytes langerhans cell merkels cells and inflammatory cells

Question 37

what is the difference between the prickle cell layer in keratinised cells and non keratinised cells

Answer 37

in keratinised- has more tonobrils and

Question 38

what is found in the granular cell layer

Answer 38

keratohyaline granules- precursor of keratin

Question 39

what is the order of layers of cells in keratinocytes (keratinised)

Answer 39

keratinised surface layer granular intermediate layer prickle cell layer basal cell

Question 40

what is the order of layers of cells in keratinocytes (non keratinised)

Answer 40

surface layer intermediate layer- doesn't contain granules of keratohyaline so it is not granulated intermediate prickle cell layer basal layer

Question 41

what are the different levels of keratin maturation

Answer 41

ortho keratin- no nuclei in superficial layer par keratin- remnants in the super facial layer non keratinised- nuclei in the superficial layer

Question 42

what is completely matured keratin called

Answer 42

ortho keratin

Question 43

where are langerhans cells found

Answer 43

in the prickle cell layer of non keratinised cells

Question 44

where are merkel cells found

Answer 44

in the basal layer of non keratinised cells

Question 45

where are melanocytes found

Answer 45

in the basal layer of non keratinised cells

Question 46

give examples of dendritic cells

Answer 46

langerhans cells merkel cells melanocyte cells

Question 47

what do langerhans cell do

Answer 47

immune/defence: antigen presentation

Question 48

what do melanocytes do

Answer 48

pigmentation:synthesis of melanin

Question 49

what do merkel cells do

Answer 49

sensory: tactile sensation

Question 50

what is the lamina propria formed of

Answer 50

the papillary layer and the reticular layer

Question 51

describe the cells the lamina propria is made out of

Answer 51

``` fibroblasts endothelial cells inflammatory cells: macrophages mast cells lymphocytes ```

Question 52

what are mast cells called before activation

Answer 52

histolytic cells- develop pseudopodia which helps them move around and surround bacteria and engulf via endocytosis

Question 53

what is the structure of the lamina propria

Answer 53

fibres ECM- contains glycoproteins and proteoglycans blood supply nerve supply

Question 54

what fibres is the lamina propria made from

Answer 54

collagen type 1 collagen type 3 2% non collagenous fibres( elastin oxytalan)

Question 55

what percentage of type 1 fibre collagen is the lamina propria made from

Answer 55

90%

Question 56

what percentage of type 3 fibre collagen is the lamina propria made from

Answer 56

8%

Question 57

what is the basal layer made from

Answer 57

the lamina lucida first then | the lamina densa

Question 58

what connects the epithelial cell to the basal layer

Answer 58

the hemidesmosomes which are connected to the lamina lucida and densa and an anchoring fibril is connected to the connective tissue

Question 59

what are the anchoring fibres made from

Answer 59

collagen type 6

Question 60

what structures are found in the submucosa

Answer 60

gland nerves artery vein

Question 61

describe the filiform papilla

Answer 61

pyramidal and are highly keratinised cover almost all surfaces of the tongue no tastebuds

Question 62

what condition can be seen which involves the filiform papilla

Answer 62

the papilla can become overgrown and overkeratinisation this in turn can cause a hairy tongue (harbours bacteria and fungi)

Question 63

describe fungiform papilla

Answer 63

look like a mushroom shape | contain tastebuds

Question 64

describe the foliate papilla

Answer 64

they are leaf shaped

Question 65

describe the pathway of taste buds

Answer 65

Taste buds detect chemicals dissolved in saliva from food in the mouth and throat. Then, these taste buds send their sensory information through neurons to the gustatory centre of the brain.

Question 66

what are the different junctions in the oral mucosa

Answer 66

mucocutaneous mucodental mucogingival