Oral Cavity Flashcards
Oral Cavity
Enclosed by dental arches, opened and closed by soft palate and tongue. Posterior border is oropharyngeal isthmus
Vestibule
External to teeth, oral fissure opens into it, opened and closed by muscles of faceial expression and by movements of lower jaw
Gingiva
- Attached - firmly bound to bone around roots of teeth
- Free or marginal - lies unattached around cervical region (cuff)
- Interdental - part of gingiva between teeth
- Mucogingival line - delineates attached from alveolar towards floor of mouth
Vermillion zone
Lips, darker skin
Vermillion border
Transition zone outlining vermillion zone
Philtrum
Verticle groove on the midline of upper lip, extending downward from nasal septum
Lips
Skin external, oral mucosa internal
Sublingual and oral submandibular salivary glands
Inferior border of oral cavity
Muscular Diaphragm
Fills between left and right sides of mandible body. Composed of mylohyoid muscles
Palate
Hard palate: anterior 2/3
Soft palate: posterior 1/3
Keratinocytes
Keratin-creating cells
Oral Epithelium
Stratified squamous, both keratinized (ortho and para) and nonkeratinized, derived from ectoderm
Oral Lamina Propria
Underlying connective tissue, epithelial (rete) pegs descend into connective tissue papillae, contain small mixed serio/mucous glands
Where types of mucosa are located?
Masticatory: Gingiva, hard palate
Lining: Lips, cheeks, floor of mouth, soft palate, ventral tongue
Specialized: Dorsum of the tongue
How does epithelial maturation differs according to function?
Layer structure
Thickness
Epithelial ridge patterns
Orthokeratinized
No nuclei in keratin layer
Parakeratinized
Small nuclei are retained
Epithelial layers
Lamina propria > Stratum basale > Stratum spinosum (prickle cells) > Stratum granulosum > Stratum corneum
Stratum basale contents
Stem cells, hemidesmosomes
Stratum spinosum contents
Desmosomes
Stratum granulosum contents
Keratohyalin granules - keratin aggregation
Lamellar granules - lipid coating
Sratum corneum contents
Anucleate then acellular layer of stacks of cross-linked keratin coated with lipid
Hard Palate layer
Epithelium: Masticatory (keratinized stratified squamous ortho/para Epithelium/CT junction: convoluted, many elongated papillae (Rete pegs) Lamina propria (CT): connected to bone
Attached gingiva CT
Many rete pegs
Free/marginal gingiva CT
Not attached to bone
Mucogingival junction layer
Epithelial changes: Attached- ortho/para keratinized
Alveolar - non-keratinized
Other Changes: attached - dense LP, many collagen bundles, attached to bone
Alveolar - LP is loose with many elastic fibers
Lining mucosa layers
Non keratinized, lacks stratum granulosum (no keratinhyaline granules)
Found in cheeks and underside of tongue, soft palate
Lips: combination of epithelia
Outside: skin
Vermillion border: thin epithelium, lots of capillaries, no salivary glands
Intermedate zone: parakeratinized
Labial mucosa: thicker epithelium, less capillaries, has salivary glands
Nonkeratinocytes
Langerhans cells - phagocyti, antigen presenting cells
Merkel cells - nerve cell, function as touch and pressure receptors
Melanocytes - pigment cells derived from neural crest cells
Filiform Papillae
Cover majority of tongue, keratinized, spine shaped
Fungiform Papillae
At tip of tongue, nonkeratinized
Foliate papillae
Posterior sides of tongue, nonkeratinized, have taste buds
Circumvallate papillae
Along junction of body and base of tonsilar area, contain taste buds, surrounded by crypts with von Ebner’s glands
von Ebner’s glands
Serous glands in crypts around circumvallate papillae, secrete serous fluid to wash out crypts
Taste buds
Only true sensory cells in oral mucosa, barrel shaped, apical ends terminate in taste pit within taste pores
Replaced continually
Saliva functions
Major secretion of oral cavity Lubricates mouth - mucous secretion Buffering - bicarbonate Digestion - amylase Protection - washes for bacteria Maintain tooth integrity Taste Tissue repair: growth factors
Haptocorrin
Produced in saliva, binds to vitamin B12 to protect it from stomach acid
3 Major salivary glands
Sublingual, submandibular, parotid
Salivary gland parts from innermost out
Intralobular: Secretory tubes, intercalated duct
Extralobular: Striated duct, excretory duct, main excretory duct
Salivary secretory units (parenchyma)
Serous demilune, mucous tubule, intercalated ducts, striated ducts
Myoepithelial cells
Squeeze product out of secretory cells
Intercalated duct
Conduct saliva
Straited duct
Striated appearance, eosinophilic cytoplasm, stains lightly pink, columnar cells
Parotid glands
Secretes alpha amylase, serous, largest gland, short striated ducts, long intercalated ducts
Mumps
Infection and swelling of parotid glands
Age related changes
Epithelium: thinner, epithelial ridges flatten, decreased langerhans cells, decreased filiform papillae on tongue, smoother, drier appearance
Lamina propria: Decreased cellularity, increased collagen, vascular changes, increased sebaceous glands of cheeks and lips
Salivary glands: atrophy with fibrous replacement and adipose tissue
