Oral Cavity Flashcards
Oral mucosa
. Stratified squamous epithelium and underlying lamina propria
. Langerhans cells, Merkel cells, and melanocytes present in epithelium
Lining mucosa of oral cavity
. Nonkeratinized epithelium
. Forms inner lining of lips, cheeks, soft palate, floor of mouth, and inf surface of the tongue
. Elastic fibers inflaming propria
Masticatory mucosa
Keratinized//parakeratinized epithelium
. Found in gingiva and hard palate
. Tall narrow CT papillae
. Mucoperiosteum as attachment to bone
Specialized mucosa in oral cavity
. Keratinized w/ papillae and taste buds
. Found on dorsal surface of tongue
Tooth components
. Crown and roots
. Formed by enamel, dentin, and cementum
Enamel
. Hardest part of body (96-98% hydroxyapatite)
. Thin layer covering tooth exposed to oral environment
. Derived from epithelium
. Secreted by ameloblasts (only present during development)
. Composed of enamel rods
. Small portion of enamel is covered by gingiva
Dentin
. Harder than bone (70% mineral)
. Most abundant dental issue
. Lies deep to enamel in the crown and deep to cementum in the root
. Organic component (type I collagen) secreted by odontoblasts
. Permeated by closely packed dental tubules traversing entire thickness
Odontoblasts
. Cell bodies aligned along inner edge of dentin
. Form peripheral body of dental pulp
Dentinal tubules
. Contain long cytoplasmic processes of odontoblasts (Tomes’ fibers)
Cementum
. Covers dentin of root
. Produced continuously of the root
. Similar to bone but avascular
. Secreted by cementoblasts that mature into cementocytes
Pulp cavity
. Hollow cavity divided into root canal and pulp chamber in crown
. Surrounded by dentin
. Filled by loose CT (tooth pulp)
. Pup is highly innervated and vascularized
Periodontal ligament
. Runs from cementum into dental alveolus in alveolar bone
. Specialized CT btw tooth and alveolar bone (connects tooth to jaw)
. Highly cellular, well vascularized
. Rich in collagen bundles
. Fibers distribute pressures fo mastication to protect bone from direct transmission of pressure
Alveolar bone
. Thin layer of compact bone that forms the wall of the alveolus
. Periodontal ligament is attached to it
. Covered by gingiva w/ mucous membrane tightly attached to underling periosteum
Tongue
. Interlacing bundles of skeletal muscles covered by oral mucosa
. Dorsal surface divided by sulcus terminalis (v-shaped groove) into anterior 2/3 and posterior 1/3
. Anterior to sulcus terminalis covered by specialized mucosa w/ papillae
. Posterior to sulcus terminalis has accumulations of lymph tissues forming the lingual tonsil in lamina propria of the base of the tongue
Papillae
Elevations of oral mucosa
Filiform papillae
. Most numerous . 2-3 mm long . Conical shape . Tips keratinized . No taste buds
Fungiform papillae
. Mushroom shaped . Visible to unaided eye . Most at tip of tongue . Not keratinized . Some taste buds
Circumvallate papillae
. Large (up tp 3 mm)
. Dome-shaped
. Surrounded by moat-like furrow
. Form 1 row of 8-12 papillae just ant. To sulcus terminalis
. Many taste buds on lat. walls w/ taste receptors
. Von Ebner ducts empty serous fluid into base of furrow to wash food material away from taste buds
Taste buds
. Small intraepithelial organs w/ neuroepithelial cells as most numerous cells
. Transducers of chemical stimuli to afferent nerve endings
Foliate papillae
Not well developed in humans
. Leaf-shaped
. Along lateral edges of the tongues
. Have taste buds
Palate
. Forms the roof of the mouth separating oral and nasal cavities
. Contains hard and soft palate and numerous submucosal glands
Hard palate
. Ant. Bony part covered by masticatory mucosa
. Adheres to periosteum
Soft palate
. Mobile
. Important during swallowing
Structure of major salivary glands
. Branches tubuloalveolar glands
. Capsule formed by dense CT that gives rise to CT septa that divide gland into lobules
Serous cells in salivary gland
. Watery secretion w/ electrolytes and enzymes
. Pyramidal cells w/ eosinophilia cytoplasm containing basophilic granules
. Similar protein-secreting cells
. Nucleus round and located near center of cell
. Basal surface rests of basal lamina
Mucous cells in salivary glands
. Thick, viscous secretion
. Pale cytoplasm
. Flattened nucleus near basal surface
Myoepithelial (basket) cells
. Contractile cells w/ numerous processes
Acini
. Secretory portion of gland
. Outer surface has contractile myoepithelial cells
. Myoepithelial cells and acting’s enclosed by basal lamina
Intralobular ducts
. Contain Intercalated ducts and striated ducts
Intercalated ducts
. Drain 2 secretory units
. W/in lobule
. Lined low cuboidal epithelium
Striated ducts
. Drain 2+ intercalated ducts
. Drain single lobule
. Simple cuboidal epithelium that becomes columnar as it approaches excretory duct
. Cells have characteristics of ion-transporting cells (basal infoldings w/ abundant mitochondria)
Excretory (interlobular and interlobar) ducts
. Btw lobules (drain them)
. Stratified cuboidal that becomes stratified columnar as duct diameter inc.
. Becomes stratified squamous as it opens into oral cavity
Saliva
. 750-1200 mL daily production
. Moistens and cleanses oral cavity
. Contains alpha-amylase to start carb digestion
. Contains lysozyme and IgA to help control microbial flora in the oral cavity
. Production under ANS control
. Sympathetic stimulation produces small amounts of protein-rich (viscous) saliva that gives feeling of dry mouth and thirst
. Parasympathetic stimulation induces production of water-rich saliva
Parotid gland
. Produces 25% of saliva
. Exclusively serous salivary gland
. Secretion rich in proteins
. High alpha-amylase activity
Submandibular salivary gland
. Produces 70% of saliva
. Mixed, mostly serous salivary gland
. 80% serous and 20% mucous
Sublingual salivary gland
. Mixed, mostly mucous salivary gland
. CT capsule not well defined
. 30% serous (only as serous demilunes) and 70% mucous
Sjorgen’s syndrome
. Autoimmune where exocrine glands (parotid) attacked
Dry mouth syndrome
. Caused by damage of salivary glands
. Common in radiation treatment of head and neck cancers
