Oral Mucosa Flashcards
What 2 tissues make up the oral mucosa?
What are the functions of oral mucosa?
- epithelium superficially (stratified squamous)
- connective tissue - underlying
Functions:
- Protection: mechanical, microbiological, chemical, prevents dehydration
- sensation: richly innervated
- secretion
- thermal regulation
Explain the mucosal distribution of oral mucosa:
Masticatory: attached gingivae, hard palate
Lining mucosa: buccal mucosa, FOM, soft palate
Specialised (gustatory) mucosa: dorsum of tongue
Non-keratinised lining mucosa
List some features of non-keratinised lining mucosa:
- undulating interface between epithelium and lamina propria
- few rete pegs
- lamina propria and submucosa
- no muscularis mucosae
- flexible
- not subjected to high stress
- stratified squamous epithelium
Basal cells: least differentiated, mitosis often visible
Prickle cells: many desmosomes connecting each cell together
Intermediate layer cells: MCGs discharge contents between cells, permeability barrier, not wholly effective. Clinically important as GTN spray can be absorbed here
Superficial cells: flattened nuclei persist, not dehydrated therefore flexible
Summarise this mucosa:
Keratinised masticatory mucosa
Lamina propria consists of papillary layer and reticular layer
- many rete pegs
- no submucosa
- thick lamina propria
- lamina propria anchored to bone
- resistant to compression
- relatively immobile
- mechanically tough
Cells beyond granular layer cells are dead, effective permeability barrier
Keratinised cells are dehydrated and not flexible
What are 10% of epithelial cells?
List its main feature and the names of these cells:
Non-keratinocytes - clear cells
- lack tonofilaments and desmosomes
include:
- merkel cells
- melanocytes
- langerhans cells
- inflammatory cells
Where are each of the papillae located on the tongue?
Green represents a minor salivary gland
Filiform: anterior 2/3rds
Fungiform: anterior 2/3rds
Foliate: lateral borders, towards back of tongue
Circumvallate: behind terminal sulcus
What is the structure of filiform papillae:
- cone shaped
- connective tissue core
- keratinised epithelial cover: tough abrasive surface
- non-keratinised epithelium in between - flexibility
Foliate papillae:
Innervation:
How many?
Innervation: anteriorly CN VII, posteriorly CN IX
- 4-11 parallel ridges
- 120 taste buds per papilla
Fungiform papillae:
Innervated:
How many?
Innervated by CN VII (carried by lingual via chorda tympani)
- 200 fungiform papillae
Anterior 1-18 taste buds
Mid tongue 1-9 taste buds
Circumvallate papillae:
Innervation?
How many?
Innervation: CN IX glossopharyngeal
3-13 circumvallate papillae per tongue
252 taste buds per papillae
What is the importance of saliva?
- essential for normal taste
- solvent and transport
- taste pores bathed in pooled saliva,fluid from serous glands of von Ebner
- taste adapted to salivary environment
- Serous glands of von Ebner:
- diffusion pathway, remove stimuli by active secretion, secrete binding proteins
