Oral mucosa

Question 1

Functions of the oral mucosa

Answer 1

protection, sensation, secretion, absorption, thermoregulation (e.g. panting in dogs)

Question 2

What does the oral mucosa provide protection against?

Answer 2

Mechanical wear and infection (immunity)

Question 3

What substance can be secreted from the oral mucosa?

Answer 3

Mucous

Question 4

How is the absorptive function of the oral mucosa utilised in medicine?

Answer 4

Fluoride absorption so it stays longer in the saliva. Drug delivery e.g. aspirin, nitroglycerine (arrhythmia)

Question 5

What are the 3 types of oral mucosa?

Answer 5

lining, masticatory and gustatory mucosa

Question 6

Where is lining mucosa found?

Answer 6

soft palate, buccal, under tongue

Question 7

Where is the masticatory mucosa found?

Answer 7

Hard palate and gingiva (around upper and lower tooth arch)

Question 8

Where is gustatory mucosa found?

Answer 8

Dorsum of tongue

Question 9

Why is there a thick lamina propria in masticatory mucosa?

Answer 9

Keeps the mucosa tight with the bone which prevents sliding during chewing. Protection during mastication.

Question 10

Why is the masticatory mucosa (para)keratinised?

Answer 10

Protection as it is exposed to friction and compressive forces during mastication.

Question 11

Alternative name for the lamina propria

Answer 11

Mucoperiosteum

Question 12

Properties of masticatory mucosa

Answer 12

(para)keratinised, thick lamina propria (mucoperiosteum)

Question 13

Properties of lining mucosa

Answer 13

nonkeratinised, loose lamina propria, wide submucosa. Mobile and distensible

Question 14

Why does lining mucosa heal the fastest?

Answer 14

Most rapid cell turn over of all oral mucosa

Question 15

Properties of gustatory mucosa

Answer 15

Keratinised, have papillae some of which bear taste buds.

Question 16

What is the general structure of the mucosa?

Answer 16

Epithelium , lamina propria, muscularis mucosae. Then submucosa, periosteum and bone.

Question 17

Which structure increases the surface area and binding between the epithelium and the lamina propria?

Answer 17

Rete ridges

Question 18

What are the cell layers within epithelium?

Answer 18

Stratum germinativum (basal cell layer), Stratum spinosum (prickle cells layer), Stratum granulosum (granular cell layer), Stratum corneum (cornified/keratinised layer)

Question 19

Which cell layer in the epithelium has no nuclei?

Answer 19

Stratum corneum

Question 20

Which is the only cell layer in the epithelium that should contain mitotic figures?

Answer 20

Stratum germinativum (basal cell layer)

Question 21

Why do the cells in the Stratum spinosum appear star shaped?

Answer 21

Due to desmosomes

Question 22

How to identify a parakeratinised epithelium on a slide?

Answer 22

Stratum corneum contains smaller, shrunken nuclei (rate of cell loss faster than rate of maturation)

Question 23

Function of cells in Stratum granulosum

Answer 23

Produce keratin (granules can be seen in cells)

Question 24

Which epithelial cell layers are not found in non-keratinised epithelium?

Answer 24

Stratum granulosum and Stratum corneum. Instead have an intermediate and superficial cell layer.

Question 25

Sequence of keratin formation

Answer 25

Membrane-coated granules found in Stratum spinosum. Tonofibrils, tonofilaments and keratohyaline granules found in Stratum granulosum. Autolysis of epithelial cells to form keratin - cells filled with closely-packed tonofilaments and surrounded by filaggrin matrix.

Question 26

Which layer is the masticatory mucosa missing?

Answer 26

Submucosa (lamina propria -> periosteum)

Question 27

What is the name of the border between the lining and masticatory mucosa?

Answer 27

Mucogingival junction (alveolar mucosa -> gingiva mucosa)

Question 28

How do you identify non-keratinocytes?

Answer 28

Clear cells - don’t contain keratin

Question 29

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

Answer 29

10%

Question 30

What are some non-keratinocytes cell types?

Answer 30

melanocytes, Merkel cells, Langerhans cells

Question 31

Function and location of melanocytes

Answer 31

Pigment-producing in Stratum germinativum

Question 32

Function and location of Merkel cells

Answer 32

Associated with mechanoreceptor neurons in Stratum germinativum

Question 33

Function and location of Langerhans cells

Answer 33

Dendritic cells (antigen-presenting cells) found about Stratum germinativum

Question 34

What are the different forms of papillae found in gustatory mucosa?

Answer 34

Filiform papillae, Fungiform papillae, Vallate papillae, Foliate papillae. Have keratinised layer.

Question 35

What is the name of the zone found on the lips between the labial (lining) mucosa and skin?

Answer 35

Vermilion zone

Question 36

What is the typical cause of geographical tongue?

Answer 36

Autoimmune response

Question 37

What are the alternative names for geographical tongue?

Answer 37

Benign migratory glossitis or glossitis migrans

Question 38

Symptoms of geographical tongue

Answer 38

Irregular, smooth patches with red or white margins which change over time. No treatment required but if discomfort is present, identify triggering foods.

Question 39

Which other autoimmune response is histologically similar to geographical tongue?

Answer 39

Psoriasis

Question 40

Examples of diseases of the oral mucosa

Answer 40

oral infections, recurrent oral ulceration, Vesiculo-bullous lesions (Herpes), white patches, premalignant conditions, pigmented lesions, oral cancer

Question 41

What is a typical sign of premalignancies?

Answer 41

Presence of keratin in abnormal locations