Lesson 7 - Part 1 Flashcards
Describe the general common properties of oral mucosa
- Oral mucosa is stratified squamous epithelium overlying
- Lamina propria which is the connective tissue proper
- Basement membrane lies between the epithelial and connective tissue layers
- Salivary glands perforate the mucosa in various regions by ducts
What are the 3 tissue types within the oral cavity?
- Lining Mucosa - floor of the mouth, ventral surface of the tongue, the cheeks, lips and soft palate
- Masticatory Mucosa - hard palate and attached gingiva
- Specialized Mucosa - dorsal and lateral surface of the tongue
What are the clinical properties of lining mucosa?
- Soft surface texture
- Moist surface
- Ability to stretch
- Ability to be compressed
- Generally pink/red in coloration
Describe the histological properties of lining mucosa
- Non keratinized stratified squamous
- Thin layer of epithelium
- Lamina propria
- Interface between epithelium and connective tissue relatively less pronounced rete pegs
- Submucosa
List the 3 sub-layers of the epithelial layer of lining mucosa
- Stratum Superficiale
- Stratum Intermedium
- Stratum Basale
List the sub-layers of the connective tissue layer of lining mucosa
- Lamina Propria - Papillary layer - loose layer; Reticular layer - dense layer
- Submucosa - loose layer
Describe the basal layer (part of epithelium) of the lining mucosa
- cuboidal cells overlying basement membrane
- Germinative: forms new cells
- Attached firmly to the basal lamina of the basement membrane
- in the thin mucosa of the floor of the mouth = one layer
- in the cheeks and soft palate = 2 or 3 layers
- subsequent maturation and migration into the upper layers – takes about 41 to 57 days for the alveolar mucosa, 25 days for the mucosa of the cheek
Describe the intermediate layer (part of epithelium) of the lining mucosa
- Large ovoid cells with abundant fluid in the cytoplasm
- Thickest layer of lining mucosa
Describe the superficial layer (part of epithelium) of the lining mucosa
- Flattened cells with small nuclei
- the plasma membrane thickens and becomes less permeable
- Non-keratinized
Describe the 2 distinct layers of the basement membrane (lining mucosa)
- BASAL LAMINA - Product of epithelium: thin zone rich in glycoproteins
- RETICULAR LAMINA - Product of CT: composed of reticular fibers and ground substance
Describe hemi-desmosomes
Basal attachment plates that anchor the epithelial cells to the basal lamina
Describe the interface between the epithelium and the lamina propria
- interdigitates
- downward ridges of the epithelium are called rete ridges or pegs
- upward projections of the LP are called connective tissue ridges or papillae
Describe the 2 layers of the lamina propria (connective tissue layer) of lining mucosa
Papillary Layer
1. Superficial layer
2. Capillary plexus
3. Loose connective tissue
4. fibers(elastic/collagen), cells and intercellular substance
Dense (Reticular) Layer
1. Dense connective tissue
2. Large number of fibers
Describe the submucosa of the lining mucosa
- Connective tissue
- Adipose tissue
- Minor salivary glands
- Firmly attached to underlying muscle
Describe labial mucosa
Intraoral of the lips:
1. Lamina propria with seromucous glands
2. Elastic fibers –ability to stretch
3. Submucosa –minor salivary glands & adipose CT with orbicularis oris muscles
Vermilion border
1. Junction of the oral mucosa and skin of the lips
2. blood vessels close to surface in thin area of epithelium
Describe buccal mucosa
- LP (lamina propria) irregular/blunt papilla with Elastic fibers –ability to stretch
- Submucosa has adipose CT
- Submucosa has mixed(seromucous) glands within the muscle fibers
- (linea alba: hyperkeratosis)
Describe the soft palate (lining mucosa)
- Highly vascularized: more pink than hard palate
- Lamina propria has numerous small blood vessels
- Submucosa with muscles of soft palate and mucous glands
Describe the ventral side of the tongue (lining mucosa)
- Dense muscle and connective tissue fibers
- Highly vascularized
Describe the floor of the mouth (lining mucosa)
- Loosely attached to lamina propria
- Minor salivary glands
- Major sublingual glands
Describe alveolar mucosa (lining mocosa)
- Thin layer of non-keratinized squamous cell epithelium
- CT papilla sometimes absent
- Elastic fibers present in LP allowing mobility
- Submucosa has minor salivary glands
- Submucosa loosely attached to underlying muscle or bone
Describe Masticatory Mucosa
Clinical Properties
1. Stippled, orange peel appearance
2. Firm and resilient
3. Light pink in color
4. Immoveable
Histological Properties
1. Keratinized epithelium
2. Epithelial layer: additional layers of cells
3. Rete pegs more pronounced giving firm base
4. Little or no submucosa
What are the 4 epithelial layers of the masticatory mucosa?
- Stratum Corneum
- Stratum Granulosum
- Stratum Spinosum (Prickle cell layer)
- Stratum Basale
Describe the CT layer of the masticatory mucosa
Contains Lamina Propria - Papillary layer (loose) & Dense layer
Describe the basal layer of the masticatory mucosa
- Single layer, cuboidal cells overlying basement membrane
- Germinative: forms new cells
- Produces the basal lamina of the basement membrane
Describe the prickle cell layer (Stratum Spinosum) of the masticatory mucosa
- Dehydrated epithelial cells due to loss of fluid
- Thickest layer of the epithelium
- Cells tend to shrink from each other and remain connected by desmosomes: spiny appearance
- Several layers thick: maturation and migration of Basal Cells
- Connected by bundles of intermediate filaments: tonofilaments, providing strength
- Melanocytes are common
- Langerhans cells: more superficial layers: initiate immune response to pathogens and to cancer
Describe the Granular Layer (Stratum Granulosum) of the masticatory mucosa
- Flat, stacked cells
- 3-5 cell layers deep
- Keratohyaline granules (chemical precursor for keratin)
Describe the Keratin Layer (Stratum Corneum) of the masticatory mucosa
- Thin, nonnucleated cells
- Cells filled with soft keratin(replaces the cytoplasm)
- Keratin: tough, nonliving material resistant to friction and bacterial invasion
Compare Orthokeratinized versus Parakeratinized cells
- Orthokeratinized - cells of keratin layer flat, no nuclei, cytoplasm filled with keratin
- Parakeratinized - cells of keratin layer flat, nuclei present, granular layer maybe absent, cytoplasm filled with keratin
Describe the interface between the
Epithelium and LP of masticatory mucosa
- Tall, narrow connective tissue papillae
- Deep Rete Pegs
- Mucoperiosteum to bone
Describe the 2 layers of the lamina propria of masticatory mucosa
Papillary (loose) layer
1. Superficial layer
2. Capillary plexus
3. Loose connective tissue
4. CT fibers
Reticular(dense)layer
1. Dense connective tissue
2. Large number of fibers
Describe the hard palate
- Orthokeratinzed squamous cell epithelium
- Thick Lamina Propria
- Rugae: folds of epithelium supported by dense lamina propria
- Anterior lateral: submucosa with fatty tissue
- Posterior lateral: mucous glandular tissue
Describe attached gingiva
- Parakeratinized squamous cell epithelium
- Lamina Propria: narrow, deep papillae directly attached to underlying bone (stippled)
Describe Specialized Mucosa
- Dorsal surface of the tongue: entire roughened surface covered with papillae
- Masticatory Mucosa: orthokeratinzied SSE, covers surface of muscle associated with the tongue
- Specialized Mucosa: four types of lingual papillae
- Papillae - Keratinic extensions of the epithelium; Four types of epithelial structures
Describe Filiform Papillae
- Slender, threadlike highly keratinized extensions of epithelial cells
- Covers majority of the surface of the tongue
- 2 – 3mm height
- Give dorsal surface of tongue velvety texture
- NO TASTE BUDS
- Aids in digestion, guiding food to pharynx
Describe Fungiform Papillae
- Few in number
- Near the tip of the tongue
- Thin epithelium, less keratinization, highly vascularized LM core
- Reddish dots, slightly raised mushroom shaped
- 1mm diameter
- Taste buds on superficial portion (not near base)
- Function is taste sensation
Describe Circumvallate papillae
- Circumvallate papillae: 7-15 large, raised, mushroom shaped structure anterior to the sulcus terminalis
- V shaped row facing pharynx
- 3-5mm in diameter
- Hundreds of taste buds in epithelium surrounding the entire base
- Van Ebner’s salivary glands in submucosa, serous minor salivary glands flush the area near the taste pores
Describe Foliate Papillae
- Lateral posterior of the tongue
- 4-11 vertical grooves
- Taste buds
- Serous glands underlying the taste buds which cleanse
- Function; taste sensation
Describe taste buds
- Barrel shaped epithelial structures
- Supporting cells and taste cells\
- Taste cells with elongated microvilli into taste pore
- Sensory nerve innervation
- Turnover 10 days
