11/6: Oral Cavity Flashcards
What is the oral cavity bounded by superiorly?
Hard and Soft palate
What is the oral cavity bounded by inferiorly?
Tongue and floor of mouth
What is the oral cavity bounded by anterior and lateral?
Teeth (dental arcade)
What is the oral cavity bounded by posterior?
Oropharynx
What is the area enclosed between lips and teeth?
Vestibule
What is the transitional zone between external haired skin and internal oral mucosa?
Vermillion border
What type of epidermis is the vermillion border?
Highly vascular dermis
Thin, overlying keratinized epidermis
What do lips lack?
Sweat and sebaceous glands
Why are the lips highly sensitive?
Rich sensory innervation
What is the oral cavity repsonsible for?
Ingestion, fragmentation, and moistening of food
What involves cutting, chewing, and grinding of food by occlusal surfaces of teeth?
Mastication
What is the bolus for swallowing (deglutition) assisted by?
Lips, tongue, and salivary gland
What is also involved in speech, facial expression, sensory perception and respiration?
Oral cavity
The anterior 2/3s of the tongue consists of a core mass of skeletal muscle oriented in 3 directions:
longitudinal
transverse
oblique
What does the posterior 1/3 of the tongue display aggregations of?
Lymphatic tissue, the lingual tonsils
What is the dorsal surface of the tongue covered by?
Nonkeratinized stratified squamous epithelium supported by a lamina propria associated with the muscle core of the tongue
What is the lining mucosa epithelium?
Non-keratinized mucosa
Where is the lining mucosa found?
Inner cheeks, floor of mouth, ventral surface of tongue and soft palate
What does the lining mucosa lack?
Stratum corneum
Where is the masticatory mucosa present?
In areas of high abrasion (gingiva (gums) and hard palate)
What kind of epithelium does the masticatory mucosa have?
Keratinized or parakeratinized (cells of stratum corneum do not lose nuclei)
What glands extend across the lamina propria and the muscle?
Serous and mucous glands
What do serous and mucus gland ducts open into?
Crypts and furrows of the lingual tonsils and circumvallate papillae
The dorsal surface of the tongue contains numerous mucosal projections called?
Lingual papillae
What is each lingual papilla formed by?
Highly vascular connective tissue core
What is the lingual papilla covered by?
Stratified squamous epithelium
What can lingual papillae be divided into?
Filiform
Fungiform
Foliate
Circumvallate
Which type of lingual papillae is most numerus?
Filliform
What is filliform papilllae made of?
Keratinized, short bristles, distributed in parallel rows
What does filiform papillae lack?
Taste buds; primarily tactile
What kind of epithelium does fungiform papillae have?
Nonkeratinized stratified squamous
Where are circumvallate papillae located?
Posterior part of the tongue, aligned in front of the sulcus terminalis
What does the circumvallate papilla occupy?
A recess in the mucosa, and is surrounded by a circular furrow or trench
What glands are associated with foliate and circumvallate papilla?
Serous glands or ebner’s glands
What do ebner’s glands open into?
Floor of circular furrows
What do Von Ebner’s glands secrete?
Lingual lipase and VEGP (von Ebner’s gland protein)
What does VEGP undertake?
Selective binding of sapid (flavorful) chemicals and their transport to taste receptors
What do ducts of serous glands (von ebner’s) empty into?
Moat
What do secretions do?
Flush area and suspend tastant particles
What do ducts of serous glands (Von Ebner gland) produce?
Von ebner gland protein (VEGP, ebnerin) that binds to taste-producing molecules. Concentrate and transport
What contain several taste buds?
Sides of circumvallate papilla
Facing wall of furrow
What does each taste bud consist of?
50-150 cells w/ narrow apical ends extending into a taste pore
What are the three cell components of a taste bud?
- taste receptor cells
- supporting cells (or immature taste cells)
- precursor cells (basal cells)
Where are ovoid chemoreceptors found in?
Fungiform, foliate, and circumvallate papillae
and on soft palate, posterior pharynx and epiglottis
What do precursor cells give rise to?
Supporting cells (or immature taste cells)
What do supporting cells (or immature taste cells) become?
Mature taste receptor cells
What does the basal portion of taste receptors cells make contact with?
An afferent nerve terminal derived from neurons in the sensory ganglia
What are the 4 classic taste sensations?
Sweet
Sour
Bitter
Salty
What is the fifth taste?
Umami (the taste of menosodium glutamate)
What are examples of bitter tastants?
Varied compounds with no common molecule structure
ex: caffeine, morphine, nicotine
What receptor is umami linked to?
Specialized receptor for L-glutamate and other amino acids
The distribution of umami receptors is ________
Unknown
Where is glutamate found?
Naturally in meats, cheeses, several cegetables
What do glutamate signalds cause?
Intake of proteinious foods
What is used as a flavor enhancer?
Monosodium glutamate (MSG)
Each taste bud can discern _____ tastes, but appear to concentrate on ______ of the five
5; 2
What do taste buds on the palate register?
Bitter and sour
What do posterior pharynx and epiglottis register?
All 5 taste buds
What protein receptor specifically responds to the flavor of fat?
CD 36
What does CD36 also funciton as?
Facilitate the uptake of fatty acids (mice release fat-digesting enzymes and increase intestinal fat absorption when they taste fat)
What does altered CD36 protein cause?
Decrease (in mice) the desire for fatty foods
What does sympathetic stimulation inhibit?
Aqueous secretion
What is aqueous secretion?
Thick, viscous saliva, rich in protein (e.g., mucus)
What does parasympathetic stimulation secrete?
Copious, watery saliva
What does saliva contain?
Watr, glycoproteins (e.g., mucus) and proteins
What specifics are found in saliva?
Enzymes - amylase, converts starch to sugar
Lysozyme
Antibacteria compounds
Ab’s - salivary IgA
High in K, low Na, high bicarbonate (HCO3-)
What is the avg saliva production in humans?
~600-1500 ml/day
What are the functions of saliva?
- Moistens oral mucosa & dry food
- Provides carrier medium for sense of taste
- Buffering via high bicarbonate content
- Digestion of carbohydrates via amylase
- Immunologic function—secretion of salivary IgA
- Control of bacterial flora
What do proteins in saliva cover teeth with?
Acquired pellicle
What does the pellicle function as?
semipermeable network of adsorbed salivary macromolecules
What provides partial protection against acidic changes?
Pellicle
What cannot completely prevent deminerlization of the tooth surface?
Pellicle
What does the pellicle have that prevents tooth decay?
Antibodies
What are the 3 major pairs of salivary glands?
Parotid
Submandibular
Sublingual
What is the largest gland, located on the cheeks?
Parotid - almost compltely serous
What does the parotid duct (stenson’s duct) open within?
Vestibule, opposite upper 2nd molarW
Where is the submandibular gland located?
Inferior and medial to ramus of mandible
What does the submandibular gland contain?
Serous and mucus glands
Where is the sublingual gland located?
Below tongue
What does the sublingual gland contain?
Mostly mucus
What is scattered throughout the oral mucosa?
Smaller, accessory glands (lingual, labial, buccal, molar, and palatine)
What is the compound (branched gands) secretory unit?
Acinus
What do myoepithelial cells surround?
Acini
What does acini contraction aid in?
Secrtion of saliva into ducts
Acini are ______ or ______
Serous; mucous
What are serous acini of mixed glands?
Demilunes
What are intercalated ducts lined by?
SImple cuboidal epithelium (secrete HCO3, resorb Cl)
What epithelium are larger striated ducts?
Simple cuboidal to columnar epithelium
What do striated ducts possess?
Basal striations, due to folding of plasma membrane
What is the function of striated/intercalated ducts?
Intercalated -
Secrete: HCO3
Resorb: Cl
Straited -
Secrete: IgA, lysozyme, K
Resorb: Na
Where do salivary glands empty into?
Larger excretory ducts
What epithelium are in excretory ducts?
Stratified cuboidal or pseudostratified columnar epithelium
what are the intrinsic muscles (4 pair)?
- superior longitudinal
- inferior longitudinal
- transversus linguae
- verticalis linguae
What is it called when we have stones in our submandibular or parotid ducts?
Sialolith
