Oral Mucosa

Question 1

What are the functions of oral mucosa?

Answer 1

• Protection (mechanical, against infection, immunity)
• Sensation
• Secretion
• Absorption
• (Thermoregulation)

Question 2

What are the 3 types of oral mucosa?

Answer 2

Lining, masticatory, gustatory

Question 3

Where is masticatory mucosa found?

Answer 3

The hard palate and gingiva

Question 4

Where is lining mucosa found?

Answer 4

Ventral surface of tongue, labial surface, buccal surface, soft palate

Question 5

Where is gustatory mucosa found?

Answer 5

Tongue dorsum

Question 6

Describe the features of masticatory mucosa

Answer 6

• Subjected to friction, compression
• (Para)keratinised
• Thick lamina propria (mucoperiosteum)

Question 7

Describe the features of lining mucosa

Answer 7

• Mobile and distensible
• Non-keratinised
• Loose lamina propria and wide submucosa
• More rapid turnover than masticatory mucosa

Question 8

Which type of mucosa is has more rapid turnover: masticatory or lining?

Answer 8

Lining mucosa

Question 9

Describe the features of gustatory mucosa

Answer 9

• Similar to masticatory mucosa
• Keratinised
• Present only on dorsum of tongue
• Characterised by papillae, some bearing taste buds

Question 10

What are the layers present in epithelium?

Answer 10

• Basal layer/stratum germinativum (mitotic cells here)
• Stratum spinosum (prickle cell layer - contains desmosomes)
• Statum granulosum (granular layer
• Stratum corneum (cornified layer - contains keratin)

Question 11

Describe the sturcture of mucosa

Answer 11

Epithelium
Lamina propria
Submucosa
Bone

Question 12

Describe the following types of epithelium:

Answer 12

• Non-keratinsed: no stratum corneum
• Parakeratinised: cornified surface. Still find some nuclei in this area
• Keratinised: Intermediate layer and superficial layer instead of granular layer and keratinised layer

Question 13

Why can lining mucosa heal faster than masticatory and gustatory mucosa?

Answer 13

Because lining mucosa is non-keratinised. Non-keratinised tissue can heal quicker as keratinisation slows the process

Question 14

Which mucosal layer is absent in masticatory mucosa?

Answer 14

Submucosa - this makes the tissue very tight

Question 15

Describe the submucosa layer in lining mucosa

Answer 15

Flexible/loose lamina propria

Question 16

Where is the mucogingival junction?

Answer 16

Between alveolar mucosa and gingiva

Question 17

What percentage of epithelial cells do non-keratinocytes account for?

Answer 17

10%

Question 18

What are melanocytes and where are they located?

Answer 18

Pigment producing cells located in the stratum germinativum i.e. the basal layer

Question 19

Where would you find Merkel cells?

Answer 19

In the stratum germinativum - basal layer

Question 20

What are 3 examples of non-keratinocytes?

Answer 20

Melcanocytes, Merkel cells and Langerhans cells

Question 21

What are Langerhans cells and where are they located?

Answer 21

Dendritic cells (DCs), found above the stratum germinativum; function as antigen presenting cells

Question 22

What are Merkel cells?

Answer 22

Mechanoreceptors

Question 23

Why is the tongue rough?

Answer 23

Due to projections called papillae

Question 24

What are taste buds?

Answer 24

Chemoreceptors: recognise specific chemicals

Question 25

What are the 3 types of papillae?

Answer 25

1. Fungiform papillae
2. Vallate papillae
3. Filiform papillae

Question 26

Where are vallate papillae located?

Answer 26

At the back of the tongue

Form a 5-7 arrangement

Question 27

Where are the taste buds located?

Answer 27

Around the vallate papillae

Question 28

Describe keratinization of papillae

Answer 28

Fully keratinised

Question 29

What is the inner portion of the lip?

Answer 29

Labial mucosa

Question 30

What is the vermillion border?

Answer 30

Demarcation between the lip and adjacent skin. Keratinised tissue

Question 31

What is geographical tongue also known as?

Answer 31

Benign migratory glossitis or glossitis migrans

Question 32

What are the features of geographical tongue?

Answer 32

• Irregular smooth patches on tongue dorsum
• No filliform papillae present in these regions
• Red or white margins
• Pattern changes over time (‘migrans’)
• Asymptomatic
• Similar to psoriasis, histologically

Question 33

What causes glossitis migrans (i.e. geographical tongue)?

Answer 33

Loss of filiform papillae

Question 34

What are the responses in glossitis migrans associated with?

Answer 34

Certain types of food - change in diet may help symptoms