Histology of Oral Cavity Flashcards
The oral mucosa is composed of ___________ epithelium overlying a connective tissue layer called the ____________.
Stratified squamous; lamina propria
What is the function of the oral mucosa?
Provides protection, sensation, and secretion
What are three basic types of oral mucosa?
-
Masticatory
- Covers areas experiencing masticatory forces
- Palate
- Gingiva
-
Lining
- Buccal, labial and alveolar mucosa
- Covers floor, cheecks, lips, soft palate
-
Specialized
- Dorsal tongue surface
Which basic type of oral mucosa is being descibed below?
- Resilent and rubbery
- Not stretcy’Forms a firm base in attached gingiva and hard palate
- Does not gape after incisions
- Painful with injection or inflammation
Masticatory
Masticatory mucosa is also known as ________.
Mucoperiosteum
Which type of oral mucosa is being described below?
- Orthokeratinized
- Overlies lamina, propria, with little or no submucosa
Masticatory Mucosa
NOTE: Masticatory mucosa is also often parakeratized
What are the characteristics of parakeratinized epithelium?
- Surface cells retain pyknotic nuclei
- The granular layer has few granules of keratohyaline (filaggrin)
- Little submucos
- Prickle layer has high density of desmosomes.
NOTE: Parakeratinized is normal for oral mucosa but abnormal for skin
Which type of oral mucosa is being described below?
- Non-keratinized
- Flexible and stretchy
- Moist
- Gapes after incision
- Injection easy, but so is spread of infection
Lining mucosa
NOTE: Lining mucosa is thicker than masticatory mucosa in most areas
Which surfaces are covered by lining mucosa?
- Inside of lips
- Cheeks
- Floow of mouth
- Underside of tongue
- Soft palate
- Alveolar mucosa
Which basic type of oral mucosa is being described below?
- Nonkeratinized stratified squamous epithelium
- Has three layers, with gradual transitions
- With migration to surface, cells enlarge, but retain nuclei and do not die
- Submucosa usaully present, overlying muscle
Lining mucosa
NOTE: Lining mucosa is very thin under tongue, which is important for drug delivery
What are the layers of lining mucosa?
- Superifical layer
- Intermediate layer
- basal layer
- Lamina propria
- Submucosa
- Muscle
The ________ contrasts the keratinized masticatory mucosa of attached gingiva with nonkeratinized lining of mucosa of alveolar mucosa.
Mucogingival Junction
Label
Characteristics of attached gingiva
- Keratinized (or parakeratinized) epithelium
- Many large collagen bundles in lamina propria to attach to periosteum (stippling)
- High rete pegs (epithelial extensions projecting into the underlying connective tissue)
- No submucosa (mucoperiosteum)
- Pale pink or darkly pigmented.
Characteristics of alveolar mucosa
- Thicker nonkeratinized epithelium
- Loose lamina propria with elastic fibers
- Thick submucosa
- Bright pink; vasculature is rich and lies near the epithelium
- Minor salivary glands in submucosa
Type of lingual papillae
- Filiform
- Circumvallate
- Fungiform
- Foliate
Which type of papillae is being described below?
- No taste buds
- Very sensitive to touch
- Cones of thick keratinized epithelium, only located on anterior 2/3rd
- Nonkeratinized areas in between
- Reduced with age
Filiform papillae
NOTE: A= Thick keritinazed epithelium; B= Nonkeratinized areas
Which type of papillae is being described below?
- Few
- Larhe
-
Each surrounded by deep trench containing taste buds
- Surface is covered by keratinized epithelium, but trench walls are nonkeratinized
Circumvallate papillae
Label
Which type of papillae is being described below?
- Scattered between filiform papillae on tip of tongue
- Red because of highley vascular core and thin epithelium
- Taste buds are most present on superior surface
- Sensitive to touch, as well as taste
Fungiform Papillae
Which type of papillae is being described below?
- Leaflike folds on lateral margin of posterior tongue
- Few taste buds in lateral walls
- Nonkeratized epithelium
- Lost with age
Foliate Papillae
*Note lymphoid tissue in opposing fold
Label
Lingual Tonsil
NOTE: Lingual tonsil is a collection of lymphoid follicles, which crypts opening onto the surface of the tongue. Covered by nonkeratized epithelium
The lingual tonsiled is lined by ________ epithelium.
Non-keratinized lining epithelium
Approximate cell turnover in oral mucosa
Label
A = enamel,
B = dentin
D = pulp,
E = alveolar bone
F = periodontal ligament
Which major component of teeth is being described below?
- Harder than bone
- Resilient, slightly elastic
- 70% mineral, 20% protein matrix, 10% water
- Smaller crystals
- Blood vessels and nerves
- Grows through life
- Can repair itself
Dentin
A= dentin
B= enamel
Dental pulp is made up of __________ tissue.
Loose connective tissue
The periodontal ligament is made of _______ tissue.
Dense fibrous connective tissue
Label
Characteristics of serous secretion
- Round nuclei in base
- Basal basophilic rER
- Extensive Golgi
- Apical secretions granules
Mechanism of serous secretion
- Active transport of ions into cell draws water in
- Apical anion channels open with parasympathetic activation, drawing ions and water into the lumen, creating and isotonic primary saliva
- As saliva moves through ducts, salt is pumped out, leaving a hypotonic saliva
___________ cells encircle acini and intecalated ducts.
Myoepithelial cells
NOTE: Myoepithelial cells lie between the epithelial secretory cells and the basal lamina
Label
SA= Serous acini
InD= Intercalated ducts
Characteristics of mucous secretion
- Nuclei flat and compressed agaist basal edge
- Apical cytoplasm filled with poorly stained mucous secretory granules
- Lumen is larger and more tubular
- Golgi and rER present, but constricted
Characteristics of minor salivary glands
- No capsule (not so painful with swelling)
- Rich in mucins, antibacterial proteins and IgA
- Slow, continuous secretion
Classification of Glands
