Oral Mucosa Flashcards
Mucous membrane - defintion?
- the moist lining of body cavities that communicate with the exterior
The oral mucosa - definition?
Mucous membrane lining the oral cavity
Oral mucosa - functions?
- protection against compressigenamd sharing forces
- barrier against organisms and toxins
- immunological defences
- secretions providing lubrication, buffering and abs secretion
- sensation of touch, proprioception, pain and taste
Oral mucosa - types? Role and anatomy?
Types:
- masticatory oral mucosa (area of high compression such as the hard palate and gingiva)
- lining oral mucosa (less compression and friction such as the lips, cheeks, alveolar mucosa, soft palate, ventral tongue and mouth floor
- specialised (top tongue, lingual tonsils, gongival attachment to teeth and vermilion border)
Oral mucosa - components? Names?
Epithelium
Lamina propria
Submucosa (for softer tissues)
Oral mucosa - Oral epithelium - characteristics?
- Stratified squamous epith (several layers)
- keratinised or non-keratinised
- ectodermal ir endodermal
- different layers according to keratinocyte differentiation
Oral mucosa - oral epithelium - layers of keratinised epithelium?
Keratinised epithelium layers:
- stratum germinstivum (stratum basale)
- stratum spinosum (prickle cell layer)
- stratum granulosum (granular layer(
- stratum corneum (keratinised or cornified layer)
Oral mucosa - oral epithelium - layers of non-keratinised epithelium?
Non-keratinised layers:
- stratum germinstivum (stratum basale)
- stratum spinosum (prickle cell layer)
- stratum intermedium (intermediate layer)
- stratum superficiale
Oral mucosa - stratum germinativum - (layers, shape, separated by, replication, differentiation, stem cells, feedback)
Progenitor cells.of keratinocytes Layers: - single Shape: - cuboidal Separated by: - from the lamina propria by basal lamina (base mem) Replication: - mitosis - daughter cells mature while ascending to other layers Differentiation: - least Stem cells: - are though to be within the ridges that project in the underlying lamina propria Feedback: - negative to inhibit further maturation
Oral mucosa - stratum spinosum - layers? Shape? Maturation? Size? Specalisim? First apperance? Obland bodies? Appearance? Deepest layers?
Layers: - several Shape: - round to avoid Size: - larger and rounder than basal cells Specialism: - cytokeratin types contribute to from tonofilaments Apperance: - involcurin Obland bodies: - intracellular granules rich in phospholipids Apperance: - spiny due to cell shrinkage Deepest layer: - parabasal layer
Oral mucosa - stratum granulosum - organelles? Shape? granules? Precursor?
Organelles: - reduced Shape: - larger and flatter cells Granules: - more keratohyaline granules Precursor: - to filaggrin
Oral mucosa - stratum cornrum - organelles? Filled with/surrounded? Desmosomes? Thickness? Para vs ortho-keratin?
Organelles: - all lost Filled with: - tonofilaments surrounded by filaggrin Desmosomes: - weakened and so allows desquamantion Thickness: - 20 cell thick Para: - has piknotic nuclei in stratum corneum Ortho: - no nuclei
Oral mucosa - non-keratinised epith - tonofilaments? Keratohyaline? Location?
Tonofilaments: - less developed Keratohyaline: - lack of Location: - intermedium and superficiale
Oral mucosa - cytokeratins - definition? #? Genes?
Defintion: - intermediate filaments specific to epith cells #: - 20 types Genes: - 2 gene families
Oral mucosa - cytokeratins - 2 gene families? Distribution?
2 gene families:
- basic type II CK (1-8, 40-56 kDa)
- acidic type I CK (9-20, 53-67 kDa)
Each epith has a pair of each gene family
Oral mucosa - cytokeratins - simple vs stratification?
Simple:
- CK 7,8 and 18
Stratified:
- CK5/15, CK 4/13 and CK1/10
Oral mucosa - cytokeratins - functions?
Functions:
- as part of the cytoskeleton
- also form part of desmosomes and hemidesmosomes
- important in metabolic integrity of cell
- CK14 related to innveration of superficial mucosa through signal transduction
Oral mucosa - cytokeratins - distribution? CK5/14? CK14? CK1/10 and CK2/11? CK4/13? CK6/16? CK19? CK5/6/14? CK7/8/18 and 19?
- CK5 and 14 restircyudd to the basal and parabasal layers
- CK14 expressed by suprabasal layer
- CK1/10 and CK2/11 expressed in suprabasal layer of masticatory mucosa
- CK4/13 in the suprabasal layers in mucosa lining
- CK6/16 assoc with rapid turnover epith
- CK19 inconsistent marker of basal layer in mucosa lining
- CK5/6 and 14 ventral tongue
- soft palate (simple keratins) CK7,8 and 18 as well as CK19
Oral mucosa - cytokeratins - clinical considerations?
- changes in CK due to inflammation
- diagnostic histopatho
- dysplastic changes revealed by CK alterations
- CK determine cyst origin
Oral mucosa - non-keratinocytes - names? Characterisitics?
Names: - melanocytes - langerhans - Merkel - inflammatory Characterisitics: - lack cells CK and all ear as clear cells in H and E stained sections
Oral mucosa - non-keratinocytes - melanocytes - Function? Location? Derivatives? Melanin production? Organelles? Cell contact? Contact? Control of melanocytes? Melanin taken up? Pigment affected by?
Function: - melanin producing cells Location: - within the basal cell.kager Derivatives: - neural crest Melanin production: - tyrosinase Organelles: - protein synthesising Cell contact: - melanosomes Contact: - up to 40 keratinocytes Control of melanocytes: - keratinocytes releases mediators important for melanocytes function Melanin taken up: - kaeratinocytes actively take up melanin by phagocyptsing the melanocytes dendritic tips Pigment affected by: - size and degree of branching melanocytes - size fo melanosomes - number and degree of dispersion of melanosomes - degree of melanisation of melanosomes - degrad rate of pigment
Oral mucosa - melanocytes - melanin pigmentation - developmental causes?
Developmental causes:
- melanin produced by melanocytes in the basal cell
- no difference in the number of melanocytes between fair and dark skinned people, diff in activity
- racial variations in the intensity and the distribution of the pigmentation
- gingiva most common site
Oral mucosa - melanin pigmentation - Peutz-Jeghers Syndrome - Gene? Pigment type? Affected areas? Fades? Other signs?
Gene: - autosomal dominant Pigment type: - mucocutaneous pigment (resembles freckles) Affected areas: - buccal and lips Fades: - during adult life Other signs: - GI polyposis (SIl
Oral mucosa - melanin pigmentation - acquired causes? Addison’s disease? Hyperkeratosis? Drug induced?
Acquired causes:
- systemic disease, malignancy or simple local disorder
Addison’s disease:
- adrenal deficiency
- elevated secretion of ACTH by pituitary
- melanocytes stim properties
- pigment in masticatory trauma areas
Hyperkaratosis:
- assocnwith melanic pigment
- lesions dusky to greyish
- smoking (melanocytic reaction to irritation)
- melanin incontinence (present in subepith macro having leaked out
- similar to lichen plants (degrad of basal cell layer)
Drug induced:
- cystostatic and oral contraceptives
- antimalarial drugs (hard palate)
- tetracycline derivative (acne), discolour bones and teeth
Oral freckle
Malignant melanoma
Oral mucosa - Langerhans Cells - what is it? Location? Derivatives? Chemokines? Movement through body? Granules? Interactions? Functions?
Characterisitics:
- dendritic cells and APCs
Location:
- above basal cell layer
Derivatives:
- of bone marrow precursor, they leave blood stream and enter lamina propria before penetrating stratum germinativum
Chemokines:
- secreted by keratinocytes act as chemotactic agent
Movement:
- from local lynoh nodes via dermal lymphatic
Granules:
- birbeck granules (rod shaped)
Interaction:
- with T lympho
Functions:
- contact hypersensitivity reaction of skin
- anti-tumour immunity
- grant rejection
- propagator of HIV1 transmission to T cells
Oral mucosa - non-keratinocytes - Merkel cells - found? Role? Derivatives? CK specific? Nuc apperance? Organelles?
Found: - in basal cell layers, close to nerve fibres and common in masticatory mucosa but absent in mucosa lining Role: - receptor Derivatives: - neural crest CK specific: - CK8/18 and 20 Organelles: - deeply invag nucleus, nuclear rodlet, mito, free ribo and granules and vesicles adj to nerve
Oral mucosa - lamina propria - 2 parts? Composition? ECM?
2 parts:
- superficial papillary layer (loose thin Col fibres)
- deep reticular layers (thick parallel collagen bundles)
Compsition:
- fibroblasts and immune cells
ECM:
- Col I 90% and Col III 8%
- small non-fibrillar collagen, elastin and oxytalan
- proteoglycans and glycoprots
Oral mucosa - epithelial connective tissue interface - Name? Components? 2 zones? Synthesis of components? Laminin? Lamina densa? Linkage?
Name:
- basal lamina
Composition:
- fibrils and ground substance
2 zones:
- lamina lucida, found immediately under epith
- lamina densa (fibroreticular lamina)
Synth:
- by epithelial cells
- lamina lucida made of laminin
Laminin:
- cements type IV Col between the lamina densa and epith cells
Lamina densa:
- made of Col IV coated with heparan sulphate
- fibronectin found and bind fibroblast and proteoglycan
Linkage:
- thick Col fibre attached to lamina densa to link basal lamina to CT
Oral mucosa - role of basal lamina?
Rolle:
- provide mechanical adhesion between epith and CT
- molecular barrier
- response to injury
Oral mucosa - submucosa - whatbis it? Contains? Composition influence?
What is it:
- layer of loose fatty or glandular CT
Contains:
- major BVs and nerves supplying the mucosa and separating it from the underlying bones and muscles
Compsition:
- determines the flexibility of the mucosal attachment to underlying structures
- minor salubery glands and serous and sebaceous present (rarelt)
- nodes of lymphoid tissue also be seen
Oral mucosa - classification - types?
Masticatory oral mucosa
Lining oral mucosa
Specialised mucosae
Oral mucosa - masticatory oral mucosa - subjected to? Covers what? Keratinised? Lamina propria?
Subjected to: - high compression and friction Covers: - the hard palate and the gingiva Epith: - keratinsied Lamina propria is thick
Oral mucosa - lining oral mucosa - subjected to? Special fucntion? Covers the? Keratinised? Lamina propria?
Subjected to: - no high friction Special function: - mobile and distensible Covers: - lips, cheeks, alveolar mucosa, soft palate, ventral surface of tongue and floor of the mouth Epith: - non-kerat Loose lamina propria
Oral mucosa - specialised oral mucosa - located?
Located:
- dorsal surface of tongue
- lingual tonsils
- gingival attachment to the teeth
- vermilion border
Oral mucosa - lip - skin/labial mucosa? Vermilion zone? Muscle type? Glands?
Mucosa: - skin on outer surface and labial mucosa on inner side Vermilion: - zone in between (transition zone, red) Muscles: - striated muscles in lip core Glands: - minor salivary gland in submucosa
Oral mucosa - skin of lip - epidermis/dermis? Glands? Hair?
Keratinised epidermis and CT dermis
Hair follicles
Sebaceous glands and sweat glands
Oral mucosa - vermilion zone - appendages? Glands? Keratinised? Lamina propria? Apperance colour? Junctional region? Infantile?
- No skin appendages
- Occasional sebaceous glands, but no mucous glands
- Keratinised
- Lamina propria has capillary loop
- Red appearance clinically
- junctional region between the vermilion zone and the labial mucosa is the intermediate zone
- parakaratinsed
- infants becomes thickened and forms suckling pad
Oral mucosa - labial mucosa - epith? Lamina propria? Submucosa composition? CT fibres?
Epith: - thick non-kerat epith Lamina: - wide with short and irregular papilla Submucosa: - many minor salivary glands CT fibres: - dense bind the mucosa to the orbicularis oris muscle
Oral mucosa - the cheek - located? Epith type? Keratinised? Submucosa composition? Muscle? Line across buccal? Ectopic gland?
Located: - buccal mucosa Epith type: - lining mucosa Keratinised: - non-kerat with dense lamina propria Submucosa: - many minor salivary Muscle: - buccinator muscle beneath glands Line: - linea alba buccalis (kerat line in the buccal mucosa along occlusal plane) Ectopic gland: - sebaceous (Fordyce's granules)
Oral mucosa - the gingiva - what is it? 2 main regions (definitions)? demarcation? gingival anatomy? gingival margin? gingival sulcus? JE? free gingival groove? principal fibres? healthy?
What is it:
- the portion of the oral mucosa that surrounds and is attached to the teeth
2 main regions:
- the attached gingiva (directly bound to the underlying bone and tooth)
- the free gingiva (narrow, not bound to any bone)
The free gingival groove demarcates the free from the attached gingiva (40% of teeth)
Oral mucosa - the gingiva - gingival anatomy? gingival margin? gingival sulcus? JE? free gingival groove? principal fibres? healthy?
Anatomy: - JE - enamel space - sulcular epith - gingival epith - gingival lig - alveolodental lig - alveolar crest Gingival margin: - is the coronal limit of the free gingiva Gingival sulcus: - the unattached region between the free gingiva and the tooth JE: - area where the gingiva is bound to the tooth Free gingival groove: - follows contours of the CEJ Principal fibres: - running from cementum to gingiva Healthy: - shows stippling, corresponding to epith ridges
Oral mucosa - attached gingiva - external surface? variations? 75% of surface? other characteristics?
External surface: - is masticatory mucosa - keratinised epith variation 75%: - parakeratinised Characteristics: - rete ridges - mucoperiosteum
Oral mucosa - free gingiva - what is it? sulcus size? depth matters?
What is it: - identical to attached gingiva Sulcus: - 0.5-2.0 is healthy Depth: - greater than 3.0mm is considered a perio pocket
Oral mucosa - sulcular epith - formation/with? compared to lamina propria? CK? characteristics? base?
Form: - sulcular and JE form the gingival cuff Compared: - more folded interface CK: - different profiles Character: - thin and non-kerat Base: - sulcus at same level as free gingival groove
Oral mucosa - JE - what is it? thinner? 2 layers? turnover rate? 2 basal laminae? lamina densa?
What is it: - junctional epithelium extends from CEJ to the sulcus base (2mm) Thinner - apically 2 layers: - stratum basale and spinosum Turnover rate: - 5/6 days 2 basal laminae: - interal (adj to enamel) and external (adj to lamina propria) Lamina densa: - internal lamina not clearly delineated (lacks Col IV and laminin)
Oral mucosa - JE - spaces? fluid passes through space? length vari? on eruption? occlusion? later on in life? recession?
Spaces: - smaller number of desmosomes result in space (5% of tissue vol) Fluid: - crevicular fluid and immune cells pass through spaces Length: - varies with the stage of eruption On erupt: - most of enamel covered by JE Later lon: - JE and CEJ Recession: - apical mig and contact with cementum
Oral mucosa - crevicular fluid - seal environment? location? course? function?
Seal environ:
- dentogingival junction seals lamina propria from oral environment
Location:
- within sulcus, results from the permeability of the JE
Course:
- pass from the lamina propria into the sulcus
Function:
- important for defence mech
Oral mucosa - interdental papilla - location? shape and size? between? interdental col? fills?
Location:
- interdental gingiva occupies area between adj teeth
Shape and size:
- depend on contact point
- wedge shaped appearance on buccal and lingual
Between:
- anterior teeth
Interdental Col:
- a curved depression across the buccolingual plane
FIlls:
- the contour around the contact point
Oral mucosa - col - what is it? kerat? spaced teeth?
Col: - epith of col continuous with the JE Non-keratinised Spaced teeth: - no col, have thin keratinised gingiva instead
Oral mucosa - gingival lamina propria - fibroblasts? less characteristics? turnover rate? rich in? histamin resp? dense Col bundles? principal fibres?
Fibroblasts: - lack alkaline phosphatase - less contractile prots, ground sub, Col III Turnover: - lower Rich in: - vasc, 2 plexi beneath the oral SE and beneath GE Histamin: - release more prostaglandin Dense Col bundles: - support fee gingiva - bind attached gingiva to alveolar bone and tooth - lankage to adj teeth Principal fibres: - divided into groups on location
Oral mucosa - gingival lamina propria - fibres?
Dentogingival Longitudinal Circular Alveologingival Dentoperiosteal Transseptal Semicircular Transgingival Interdental Vertical Oblique Apical Interradicular
Oral mucosa - alveolar mucosa - what is it? location? characteristics? attached to
What is it:
- attached gingiva is demarcated from the
alveolar mucosa by the mucogingival junction
Location:
- 3-5mm below the alveolar crest
Characteristics:
- non-kerat, loose submucosa (elaston), BVs near surface and minor salivary
Attached to:
- submucosa attached to periosteum
Oral mucosa - hard palate - mucosa type? epith type? submucosa exists? nasal surface lining? type of submucosa?
Mucosa type: - masticatory Epith type: - keratinised Submucosa: - none present especially centrally - exists where the palate meets the alveolus (contains main neurovascular bundle) Nasal surface: - lined with respiratory epith - ciliated columnar epith with goblet cells Type of submucosa: - vascular submucosa with minor glands
Oral mucosa - soft palate - epith type? histo description? submucosa?
Epith type: - non keratinised Histo description: - short broad CT papillae submucosa: - with many salivary glands
Oral mucosa - floor of the mouth - FoM and ventral tongue lining? function? epith type? submucosa? lamina propria?
FoM and ventral tongue lining:
- both the floor of the mouth and the ventral surface of the tongue have a typical lining mucosa
Function:
- need for mobility
Epith type:
- thin, non keratinised epithelium with short
papillae
Submucosa:
- submucosa considerable for the floor of the mouth, but almost absent for the ventral surface of the tongue
Lamina propria:
- highly vasc (drug route)
Oral mucosa - tongue - split? cover 2/3? has lots 1/3? types of papillae? filiform? kerat? central core? papillae (function)
Split: - anterior 2/3 are divided from the post 1/3 by sulcus terminalis Cover 2/3: - covered with papillae Has lots 1/3: - lymphatic nodules Types of papillae: - filiform, fungiform, foliate and circumvallate Filiform: - largely cover the ant 2/3 of dorsum tongue Kerat: - yes (para or ortho) Central core: - of lamina propria with 2nd papillae branch Function: - highly abrasive (mechanical)
Oral mucosa - tongue - fungiform papillae - location? size? epith type? core? also found here?
Fungiform: - found as isolated elevated mushroom shaped papillae between filiform Size: - 150-400um Epith type: - kerat or non-kerat Core: - vasc lamina propria also found: - taste buds on surface
Oral mucosa - tongue - foliate papillae - located? epith type? other found?
Foliate:
- may be found as 1-2 longitudinal clefts at the side of the posterior part of the tongue
Epith type:
- non-kerat
Other found:
- taste buds maybe found within their epithelium
Oral mucosa - tongue - circumvallate - size? surrounded by? projection? epith type? other found?
Size: - large and rounded surrounded by: - trench like structures projection: - not beyond surface of tongue Epith type: - non-kerat other found: - taste buds on lateral wall of trenches
Oral mucosa - tongue - Von Ebner’s glands - type? empty into?
Von Ebner's - serous gland Empty into: - base of trenches Mucous glands also present
Oral mucosa - tongue - taste bud - what is it? types? opening? types of cells? sensory cell types (appearance)? I and III form? separate bud from?
What is it: - a chemoreceptive organ of taste Types: - circumvallate, fungiform and foliate Opening: - small pore opens from surface into bud types of cells: - tase and supporting cells Sensory cell types: - I (appear dark) - II (appear light) - III (appear light) - IV (are undiff, lay basally and possess intermediate filaments) I and III: - form synapses with intrageminal nerves Separate: - basal lamina separates bud from lamina propria
Oral mucosa - lingual tonsils - what are they? Part of? deep crypts? gland presence?
What are they:
- masses of lymphoid tissue on the lateral
border of the posterior third of the tongue
Part of:
- Waldeyer’s ring (lingual, palatine and pharyn)
Deep crypts:
- lined with epith containing masses of lymphoid tissue
Gland:
- mucous gland
