Oral Mucosa Flashcards
What are the major components of oral mucosa/epithelium?
Stratified squamous–> avascular
Basement membrane–> divides epithelium & CT
Connective Tissue–> underlies epithelium & contains vascular & neural elements
What are the functions of oral mucosa?
Protective Secretory Taste* Absorption Sensory
What are the 3 types of oral mucosa?
Masticatory
Lining
Specialized
Where is masticatory mucosa found?
Hard palate
Gingiva
Dorsum of tongue
What types of epithelium is masticatory mucosa composed of?
Parakeratinized and orthokeratinized epithelium
Para= immature form of ortho
Which type of mucosa has the fastest cell turnover time? Longest?
Lining= fastest @ 4-12 days Masticatory= longest @ 12-24 days
What are the cell layers of masticatory mucosa?
Stratum Germinativum/basal layer
Stratum Spinosum/Prickle layer
Stratum Granulosum/granular layer
Stratum corneum/keratin layer
Which type of epithelium has cells that contain only keratin and no nuclei?
Orthokeratinized
Which type of epithelium has cells that contain keratin and nuclei but no organelles?
Parakeratinized
What are microplicae?
Cellular ridge-like folds/may produce mucin for protection of tissue surface
Function of melanocytes and their embryonic origin
Produce melanin, derived from CT
Embryology= neural crest cells
Function of Granstein & Lagerhans cells
Antigen processing/act as phagocytes
Function of Merkel cells
Clear cells with tactile receptors & react to pressure
Where is lining mucosa found?
Labial, buccal and alveolar mucosa; sulcus, junctional epithelium, col region, floor of mouth, ventral surface of tongue & soft palate
What type of epithelium makes up lining mucosa?
Stratified squamous nonkeratinized epithelium
Cell layers of nonkeratinized stratified squamous epithelium
- Stratum basal- same as germinativum
- Stratum intermedium- corresponds w/ spinosum (larger cells, fewer intercellular bridges)
- Stratum superficiale- coresponds w/ corneum, nuceli are normal, organelles present
Where is specialized mucosa found? why is it specialized and what is its function?
Dorsal and lateral surfaces of tongue
Combo of masticatory and lining mucosa
taste function
Function of basement membrane? What are the two portions?
Divides epithelium and CT, two portions come one from each layer
What are the 2 layers of the basal lamina?
Lamina lucida- outer clear layer (closest to epithelium)
Lamina densa- Inside dense layer (closest to CT)
What is the attachment mechanism for the basal lamina?
Hemidesmosomes w/ attachment plaques
Tonofilaments
What are epithelial ridges/rete ridges and where are they located?
Concave and curving side of the basal lamina
Increases surface area contact to CT
Located throughout all oral mucosa but most prominent in masticatory
What is the epithelial component of the basement membrane?
Basal lamina- 2 layers, thin, collagenous network
What is the CT component of the basement membrane?
Lamina reticularis- one layer, thick, ACELLULAR, collagenous network
What is the attachment mechanism of the lamina reticularis?
Anchoring fibers; penetrate and pierce the lamina densa above it, interacts with hemidesmosomes and tonofilaments, stabilizes epithelial cells
What are connective tissue papilla?
Convex, curved area of the lamina reticularis side of the basement membrane
Increases surface area contact to EPITHELIUM
Most prominent in masticatory mucosa
Cells of subepithelial CT
Fibroblasts Myofibroblasts Mast cells Macrophages Tissue WBC's
What do fibroblasts produce in subepitheial CT?
Collagen, reticulin, elastin fibers and ground substance
What do myofibroblasts produce in subepithelial CT?
Modified fibroblasts (PDL, gingiva, wound healing)
Combo of fibroblasts and muscle cell= contractile
Also assoc. with eruption
WHat do mast cells produce?
Heparin
Histamine
What are the tissue WBC’s?
PMN’s, eosinophils, lymphocytes, monocytes
What are the tissue layers of the subepithelial CT?
Lamina propria Submucosa layer (deep ayer)
What does the lamina propria layer contain?
Collagen fibers
My contain elastic fibers
What is teh attachment mechanism for the lamina propria?
Interdigitates w/ epithelium along the lamina reticularis/CT papilla
WHat are the 2 layers of the lamina propria?
Papillary layer (closest to epithelium)- loose CT, BV/nerves Dense layer (below papillary)- dense CT, lots of collagen
What is the submucosa layer and what does it attach to?
Loose CT that attaches to deeper structures
Thick: attach to muscle- soft palate
Thin: attach to bone- gingiva, hard palate, alveolar mucosa
What supplies blood to the lamina propria?
Capillary plexus
What supplies blood to the submucosa layer?
BV
What is the external surface of the lips and cheeks?
Epidermis
What is the epithelial component of the lips and cheeks?
Keratinized epithelium w/ dermis (CT) and has increased amount of rete ridges & CT papilla
What is the vermillion zone?
Specialized epidermis
Red zone, keratinized epithelium w/ dermis & has increased amount of rete ridges and CT papilla
WHat does the vermillion zone form?
Mucotaneous junctions: Jct. of epidermis and labial mucosa, commisures of lips
What type of mucosa is the labial and buccal mucosa?
Lining mucosa
Thick, nonkeratinized epithelium w/ lamina propria
Increased rete ridges & CT papilla
Describe the submucosa layer (CT) of the labial and buccal mucosa
Loosely attached to muscle, contains minor salivary glands
Associated structures: Lips- labial frenum. Cheeks- buccal frenum, linea alba, fordyce granules, parotid papilla, buccinator muscle, buccal fat pad
What type of mucosa is alveolar mucosa?
Lining mucosa
Covers alveolar ridge but not the hard palate
Describe the epithlium of the alveolar mucosa
Thin, nonkeratinized epithelium w/ lamina propria & has decreased amounts of rete ridges and CT papilla
Describe the attachment of the submucosa layer of the alveolar mucosa
Loosely attached to periosteum of bone and contains minor salivary glands
What are the associated structures of alveolar mucosa?
MGJ: junction of alveolar mucosa and attached gingiva
Where is the gingiva located?
Extends from the GM to the MGJ
What type of epithelium is gingiva? Describe the epithelial components
Masticatory mucosa
Thick para/orthokeratinized epithelium
Increased rete ridges/pegs
Lamina propria has increase CT papilla
So submucosal layer
What are the 5 gingival ligaments that support the gingiva and are not considered part of the periodontium?
Circular Alveogingival Dentoperiosteal Dentogingival Transseptal/Interdental
Where is the sulcular epithelium located?
From the sulcus to the col area
What type of mucosa is sulcular epithelium? describe
Lining mucosa
Extremely thin, nonkeratinized epithelium
Decreased rete pegs
Has lamina propria and decreased CT papilla
No submucosal layer
Where is free gingiva located?
GM to free gingival groove, coronal to attached gingiva
What is the gingival margin?
Most coronal part of free gingiva
Junction between free gingiva and gingival sulcus
What is the free gingival groove?
Depression that demarcates the end of free gingiva, beginning of attached gingiva
Level w/ floor of sulcus
May not be prominent/visible
What is the gingival sulcus?
Shallow groove that separates free gingiva from surface of tooth
Extends from GM to junctional epithelium (bottom of pocket)
What is the function of gingival crevicular fluid?
Provides adhesion, defense and participates in inflammatory response
What is junctional epithelium? Function?
Forms floor of gingival sulcus
Attaches gingiva directly to the tooth surface using hemidesmosomes
At same level of free gingival groove
Where is attached gingiva? What is its attachment?
Extends from free gingiva to MGJ
Attaches to alveolar bone
What are interdental papilla?
Tissue that fills space between 2 adjacent teeth
What are the 3 regions of interdental papilla?
Labial/buccal and lingual/palatal surfaces- pyramid shape, contains gingival ligaments
Col region- Crater-like depression of IP. Located below contact area of adjacent teeth
What innervates the alveolar bone?
Subperiosteal arteriole and branches of Zuckerkandle & Herschfelds
What vascularizes the gingiva?
Maxillary artery
PDL vessels/ dental branches
What innervates the gingiva?
Trigeminal nerve
PDL nerve branches/dental branches
Alveolar bone/ subperiosteal nerves
Describe the epithelial qualities of junctional epithelium
Nonkeratinized lining mucosa
No retepegs or CT papilla
Wedge-shaped and continuous w/ sulcular epithelium
Located on tooth, forms floor of gingival sulcus
What is the function of the external basal lamina of JE?
Composes the basement membrane
Separates epithelium cells and lamina propria
What are the layers of the external basal lamina/basement membrane?
Lamina lucida- closest to epithelium
Lamina Densa-
Lamina reticularis
What is the function of internal basal lamina?
Attaches epithelium to the tooth via hemidesmosomes
High mitotic activity- cells move from EBL to IBL- desquamate through sulcus
What are the layers of internal basal lamina?
Lamina lucida- closest to epithelial cells
Lamina densa- closest to tooth surface
What is the attachment mechanism for Internal and external basal lamina?
Hemidesmosomes attach basal lamina to enamel
Starts on enamel but could eventually reside on cementum or even dentin
When does JE form?
Established during tooth eruption
How does JE form?
REE and oral epithelum fuse utilizing desmosomes–> Forms primary epithelial attachment
PEA is replaced by oral epithelium forming JE and secondary epithelial attachment
What kind of epithelium makes up the hard palate? Describe the epithelium
Masticatory mucosa
Thick para/orthokeratinized epithelium
Increased rete pegs
Describe the subepithelial CT of the hard palate
Subepithelial CT has lamina propria with increased CT papilla
Firmly bount to periosteum- part of mucoperiosteum
Submucosal layer present in lateral zones
Associated structures of the hard palate
Raphe, gingival region, rugae, incisive papilla, fovea, minor slivary glands
Vascularization and innervation of hard palate
Branches of nasopalatine and palatine arteries and nerves
Describe the epithelium that makes up the soft palate
Lining mucosa
Thin, nomkeratinized epithelium
Increased rete ridges
Describe the subepithelial CT of the soft palate
Thick lamina propria
Increased CT papilla w/ elastin layer
Attaches to epimysium
Contains MSG’s
Vascularization and innervation of soft palate
Lesser palatine artery and nerve
Describe the epithelium of the uvula
Lining mucosa
Nonkeratinized epithelium
Increased rete pegs
Describe the subepithelial CT of the uvula
Lamina propria has increased CT papilla
SUbmucosal layer attaches to epimysium of muscle core
Describe the epithelium of the nasopharynx/nasal surface of palate
Hard and Soft palate: Pseudostratified columnar epithelium
Posterior soft palate: nonkeratinized epithelium
Describe the subepithelial CT of the nasopharynx
Lamin propria and submucosal layer
Similar to hard/soft palates
Contains MSG’s
Describe the epithelium of the body/dorsum of tongue- Anterior 2/3
Specialized mucosa
Para, ortho and non keratinized epithelium (mixed)
Describe the subepithelial CT of the body/Anterior 2/3 of tongue
Lamina propria has increased CT papilla
Submucosal layer attaches to epimysium of muscle core
What kind of epithelium make up the lingual papilla? What are the 4 kinds of lingual papilla?
Keratinized epithelium
Filiform- abrasive/no taste
Fungiform- taste
Foliate- taste and vin ebner salivary ducts
Circumvallate- taste and von ebner
What are the components of taste buds?
Taste pore- Opening on the top of taste buds Taste hair- taste receptors Taste bud- Origin of taste Taste cells- produce taste sensation Supporting cells- support taste cells
What vessel provides blood supply to the tongue?
Lingual artery
What nerves provide general sensory to the tongue?
Trigeminal- body
Glossopharyngeal- root
What nerves provide special sensory for the tongue?
Facial
Glossopharyngeal
Vagus
What are the motor nerves of the tongue?
Facial
Glossopharyngeal
Hypoglossal
Describe the glands of Von Ebner (middle)
Pure serous (watery) Posterior 1/3 of tongue Open into circumvallate and foliate papilla
Describe the glands of Blandin Nuhn (anterior)
Mixed gland (serious/mucus) In tip of tongue Open into plica fimbriata on ventral surface
Describe posterior mucus gland (posterior)
Pure mucus gland (thick)
In posterior 1/3 root of tongue
Open into tonsillar crypts of tongue
Describe the epithelium of the posterior 1/3 of the tongue
Lining mucosa
Nonkeratinized and decreased rete pegs
Describe the subepithelial CT of the posterior 1/3 of tongue
Lamina propria has increased CT papilla
Attached to epimysium of muscles
Associated structures of posterior 1/3 of tongue
Sulcus terminalis- jct of body and root
Foramen cecum- depression posterior to sulcus terminalis (thyroid)
Lingual tonsil- lateral surface
Tonsillar crypts- crevices of lingual tonsils
Describe the epithelium of the ventral surface of the tongue
Lining mucosa
Thin, nonkeratinized
Decreased rete pegs
Describe the subepithelial CT of the ventral surface of the tongue
Lamina propria has decreased CT papilla
Submucosal layer is loosely attached to muscle epimysium
Great range of movment
Where can hyperkeratinized epithelium occur?
On non/para/orthokeratinized epithelium
Examples of hyperkeratinized epithelium
Linea alba on buccal mucosa from localized trauma
Fibrosis of attached gingiva from advanced perio disease
Nicotine stomatitis on hard palate
In oral vestibules from chewing tobacco
What can give rise to squamous cell carcinoma of the oral mucosa?
Alcohol use, tobacco use and HPV
Increase risk of oral cancer with these conditions