Oral Mucosa And Gingiva Flashcards
Describe the layers above basal lamina/basement membrane in masticatory mucosa
Masticatory mucosa is keratinised
Basal layer: single cell layer, stem cells
Prickle layer: several cells thick, ovoid keratinocytes joined together by desmosomes
Granular layer: keratinocytes larger and fatter, organelles reduced or lost. Keratinohyaline granules contain gilaggrin which bind to tonofilaments to form keratin network. Keratinohyaline release lipid rich contents into intercellular space to cement layer and reduce water loss
Keratinised layer: up to 20 cells thick. Keratinocytes no organelles. She’d through desquamation.
Interface between epithelium and lamina propria highly interdigitated with rete pegs (epithelial extensions) that give firm support
Function for keratinised layer in masticatory mucosa
Mechanical protective function
Disulphide crosslinking provide mechanical and chemical resistance
Function of rete pegs
Epithelial extension that project into connective tissue
Better attachment to disperse forces applied at epithelium over larger area
Increased metabolic exchange between epithelium and vasculature
List the 3 different types of oral mucosa
Lining mucosa: buccal/labial mucosa, alveolar mucosa, soft palate, ventral surface of tongue
Soft pliable texture, distensible, increased concentration of capillaries and less keratinisation makes it redder
No keratinohyaline granules
Masticatory mucosa: attached gingiva, hard palate, dorsal surface of tongue
Rubbery and firm, at areas with high compression and friction
Gastatory / specialised mucosa: dorsal surface of tongue, associated with papilla and taste buds
5 functions of oral mucosa
Protective against shearing and compressive forces
Sensory as richly innervated
Saliva: salivary ducts and glands for lubrication and buffering
Immunological defence: Langerhans cells in lamina propria
Barrier to bacteria and toxins
Cells present in lining mucosa
Melanocytes
Langerhans cells
Merkel cells
Function of lamina propria
Mechanical support
Nutrition
Sensory
Defence via saliva and immunocompetent
What are the two layers of the lamina propria
Superficial papillary layer between rete pegs, collagen fibres thin and loosely arranged
Deep reticular layer dominated between thick parallel bundles of collagen fibres
Cell types in oral mucosa
FIBROBLAST
- stellate, abundant RER
- secrete fibres
- throughout lamina propria
HISTIOCYTE
- spindle shaped/stallate, dark stained nuclear, many lysosomal vesicles
- precursor of macrophage
MACROPHAGE
- pale staining nucleatum
- meant lysosomes and phagocytes vesicles
- phagocytosis, antigen processing
MAST CELL
- round, basophils granules
- sects inflammatory mediators
NEUTROPHIL
- lobed nucleus
- lysosomes and specific granules
- phagocytosis and cell killing
- at areas of acute inflammation
LYMPHOCYTE
- dark staining nucleus
- scant cytoplasm
- immune response
- at areas of acute and chronic inflammation
PLASMA CELL
- cartwheel nucleus
- abundant RER
- synthesis immunoglobulins
- at areas of chronic inflammation
ENDOTHELIAL CELL
- contain pinocytotic vesicles
- line blood and lymphatic channels
- associated with basal lamina
What glands are present in submucosa
Minor salivary and sebaceous
Blood supply of upper lip
Superior labial artery (anastomoses with buccal artery)
Blood supply of upper gingiva
Anterior: anterior superior alveolar artery
Lingual: sublingual artery
Buccal: buccal artery
Posterior: posterior superior alveolar artery
Blood supply of hard palate and soft palate
Major palatine artery, nasopalatine artery, sphenopalatine artery for hard palate
Minor palatine artery for soft palate
Blood supply of cheek
Buccal artery, infra orbital artery, posterior alveolar artery
Blood supply of lower lip
Inferior labial artery, mental artery, branch of inferior alveolar artery
Blood supply of lower gingiva
Anterior buccal: mental artery
Anterior lingual: incisive and sublingual artery
Posterior lingual: inferior alveolar and sublingual artery
Posterior buccal: inferior alveolar and buccal artery
Blood supply of tongue
Anterior 2/3: deep lingual artery
Posterior third: dorsal lingual artery
Nerve supply to upper lip and vestibule
Twigs from infraorbital branch of maxillary nerve
Nerve supply to upper gingiva
Anterior, posterior, middle superior alveolar branches of maxillary nerve
Alveolar —> teeth!
Hard palate innervation
Sphenopalatine branches of maxillary nerve
Soft palate innervation
Lesser palatine branch of maxillary nerve, tonsillitis branch of glossopharyngeal nerve, nerve of pterygoid canal originating from facial nerve
Innervation of cheek
Infraorbital branch of maxillary nerve, superior alveolar branch of maxillary nerve, buccal branch of mandibular nerve
Lower lip and vestibule innervation
Mental branch of inferior alveolar branch of mandibular nerve, buccal branch of mandibular nerve
Innervation of lower gingiva
Inferior alveolar branch fo mandibular nerve, buccal branch of mandibular nerve, sublingual branch lingual of lingual nerve
