Oral Mucosa Flashcards
What are the 3 functions of oral mucosa?
- Protection (against mechanical forces, microbial invasion, toxins, antigens)
- Sensation (touch, proprioception, taste, pain)
- Secretion (lubrication from minor salivary glands)
Name the 3 classifications of the oral mucosa
- Masticatory mucosa
- Lining mucosa
- Specialised mucosa
Provide examples of where masticatory mucosa is found
- Gingiva (free & attached)
- Dorsal surface of tongue
- Hard palate
Provide examples of where lining mucosa is found
- Ventral surface of tongue
- Labial/buccal mucossa
- FOM
- Alveolar mucosa
Provide examples of where specialised mucosa is found
- Vermillion border
- Dorsal surface of tongue (taste buds)
What are the 4 layers of the oral mucosa?
- Epithelium
- Lamina propria
- Submucosa (adipocytes & glands)
- Bone
What are the 4 layers of the oral mucoperiosteum?
- Epithelium
- Lamina propria
- Periosteum
- Bone
What is the key structural difference between the oral mucosa and oral mucoperiosteum?
Oral mucosa has submucosa
Oral mucoperiosteum does not have submucosa, instead has a periosteum
What are the layers of the keratinised epithelium?
- Keratinised layer (stratum corneum)
- Granular layer (stratum granulosum)
- Prickle layer (stratum spinosum)
- Basal layer (stratum basale/ germinativum)
What are the layers of non-keratinised epithelium?
- Superifical layer
- Intermediate layer
- Prickle layer
- Basal layer
What are the histological differences between the orthokeratinised and parakeratinsed epithelium?
- Orthokeratinised epithelium has a more prominent granular layer compared to parakeratinised epithelium
- Orthokeratinised epithelium appears more pale pink compared to parakeratinised epithelium
- Orthokeratinised do not contain nuclei in the keratinised layer; Parakertainised contains nuclei in the keratinised layer
Name the 4 non-keratinocytes in the oral epithelium
- Melanocyte
- Langerhans cell
- Merkel cell
- Lymphocyte
Where are melanocytes located in the oral epithelium?
Basal layer
What is the function of the melanocyte?
- Melanosome synthesis (melanin pigment of granules)
2. Transfer of melanosome to surrounding keratinocytes
Where are Langerhans cells located?
Suprabasal layer
What is the function of the Langerhans cell?
Antigen-trapping & processing
Where are Merkel cells located?
Basal layer
What is the function of the Merkel cell?
Tactile & sensory
Where are lymphocytes located?
Variable
What is the function of lymphocytes located?
Part of the inflammatory response in oral mucosa
What specific stains would allow histologists see the following cells under the microscope?
- Melanocytes
- Langerhans cell
- Merkel cell
- Lymphocyte
- Dopa oxidase-tyrosinase silver stains
- Cell surface antigen markers
- Acid-schiff positive
- Cell surface antigen markers
Name the 8 cells in the lamina propria
- Fibroblast
- Histocyte
- Macrophages
- Mast cell
- Polymorphonuclear leukocyte (neutrophil)
- Lymphocyte
- Plasma cell
- Endothelial cell
List the functions of the following cells:
- Fibroblast
- Histocyte
- Macrophages
- Mast cell
- Polymorphonuclear leukocyte
- Lymphocyte
- Plasma cell
- Endothelial cell
- Synthesis of CT fibres & ground substance
- Precursor of macrophages
- Phagocytosis & antigen-presenting
- Secretion of inflammatory mediators & vasoactive agents (usually involved in immediate allergy reactions) e.g. Histamine, heparin, serotonin
- Phagocytosis & cell-killing
- Humoral & cell-mediated immune response (adaptive immunity)
- Synthesis of immunoglobulins (antibodies)
- Lining of blood & lymphatic channels
What are the 4 factors that determine the colour of the oral mucosa?
- Concentration & dilation state of BV’s in underlying CT
- Degree of keratinisation
- Epithelium thickness
- Amount of melanin pigment in epithelium
List the possible factors you would see a red-coloured oral mucosa
- Thin epithelium
- More BV’s
- No keratin
List the possible factors you would see a pink-coloured oral mucosa
- Thick epithelium
- Fibrous lamina propria
- Less BV’s
- Thick keratin
What are fordyce granules?
Ectopic sebaceous glands located on the buccal mucosa & lip vermillion border