Oral Cavity Histo Flashcards
What area is enclosed between the lips and teeth?
vestibule
What is the oral cavity bound by?
hard and soft palate
tongue and floor of mouth
teeth
anterior and lateral orpharynx
What is the superior boundary of the oral cavity?
hard and soft palate
What is the anterior and lateral boundary of the oral cavity?
labium/lip, cheek, and body of the tongue
What is the inferior boundary of the oral cavity?
geniohyoid and mylohyoid muscles supporting the floor of the mouth
What is the posterior border of the oral cavity?
uvula, palatine tonsil, root of the tongue, and the lingual tonsil
What is the transitional zone between external haired skin and internal oral mucosa?
vermillion border
What creates the color of the oral cavity?
higher vascularized dermis and thin, overlying keratinized epidermis
What kinds of glands do the lips lack?
sweat and sebaceous glands
What is the oral cavity’s function?
ingestion
framentation
moistening
mastication
deglutition
speech
facial expression
sensory perception
respiration
What is mastication?
cutting, chewing, and grinding of food by occlusal surfaces of the teeth
What is created by the process of mastication?
a bolus of food
What is another term for swallowing?
deglutition
What does the anterior 2/3rds of the tongue consist of?
core mass of skeletal muscle (longitudinal, transverse, oblique)
What is the posterior 1/3rd of the tongue consist of?
aggregations of lymphatic tissue (lingual tonsils)
How many cranial nerves innervate the tongue?
5
How many pharnygeal arches help to develop the tongue?
4
What is the dorsal surface of the tongue covered by?
nonkeratinized stratified squamous epithelium supported by lamina propria
What is the lining mucosa? (oral cavity)
non-keratinized mucosa found on inner cheeks, floor of mouth, ventral surface of tongue and soft palate
What layer of skin does the lining mucosa not have?
lacks stratum corneum
Where is the masticatory mucosa?
present in areas of high abrasion (gingiva and hard palate)
What type of cells are in the masticatory muscoa?
keratinized and nonkeratinized
What are the four pairs of intrinsic muscles of the tongue?
-superior longitudinal
-inferior longitudinal
-transversus linguae
-verticalis linguae
What is the on the dorsal surface of the tongue?
numerous mucosal projections called lingual papillae
What are lingual papillae formed from?
highly vascular connective tissue core and a covering layer of stratified squamous epithelium
How are the four types of lingual papillae divided?
based on their shape
What are the form types of lingual papillae?
filiform, fungiform, foliate & circumvallate
What type of lingual papillae are the most numerous?
filiform papillae
What type of lingual papillae do not have taste buds?
filiform papillae
-mostly tactile
What are the characteristics of filiform papillae?
keratinized, have short bristles, and are distributed in parallel rows
What are the characteristics of fungiform papillae?
nonkeratinized stratified squamous
has taste buds along apical surface
What are the characteristics of foliate papillae?
parallel rows
taste buds in lateral walls
What are the characteristics of circumvallate papillae?
occupies a recess in the mucosa and is surrounded by a circular furrow or trench
Where are circumvallate papillae located?
posterior part of the tongue; aligned in front of the sulcus terminalis
What are the serous (Ebner’s glands) associated with?
foliate and circumvallate papillae
Where do the ducts of the Ebner’s glands open into?
into the floor of the circular furrows
(into the moats)
What do the serous (Ebner’s) glands secrete?
lingual lipase and VEGP
What does VEGP (von ebner’s gland protein) do?
undertakes the selective binding of sapid (flavorful) chemicals and their transport to taste receptors
(present chewed food to the tastebud)
Where are taste buds?
on the sides of circumvallate papilla and face the wall of the furrow
How many cells are in taste buds?
50-150 cells
-narrow apical ends extend into a taste pore
What are the three components of the taste bud?
(1) taste receptor cells
(2) supporting cells (or immature taste cells)
(3) precursor cells (or basal cells)
Where are ovoid chemoreceptors found?
fungiform, foliate, circumvallate papillae
(on the soft palate, posterior pharynx, and epiglottis)
What is the lifespan of cells in the taste receptor?
10-14 days
What do taste receptor precursor cells do?
give rise to supporting cells which become mature taste receptor cells
What does the basal portion of a taste receptor cell make contact with?
an afferent nerve terminal derived from sensory ganglia
(facial, glossopharyngeal, and vagus nerves)
What are the four classic taste sensations?
sweet, sour, bitter, salty
What is the fifth taste sensation?
umami (MSG)
What are other bitter tastants?
varied compounds with no common molecular structure (caffeine, morphine, nicotine)
What is umami linked to?
a specialized receptor for L-glutamate and other amino acids
Where are glutamates naturally found?
meats, cheeses, several veggies
What does glutamate signal?
presence of proteins and causes the intake of proteinious foods
Each taste bud can discern all five tastes but appear to concentrate on _______ out of five.
two
Taste buds on the palate register primarily _______ & ____.
bitter and sour
What modalities do the posterior and epiglottis taste buds register?
all five
What protein receptor specifically responds to the flavor of fat?
CD 36
What does CD 36 do?
facilitate the uptake of fatty acids
-may also increase the preference for fatty foods
What is the new taste modality for?
complex carbohydrates
What type of saliva does sympathetic stimulation cause?
thick, viscous saliva, rich in proteins
(muscusy)
What type of saliva does parasympathetic stimulation cause?
copious, watery saliva
What does saliva contain?
water, glycoprotines, proteins, enzymes, antibodies, K, bicarbonate
What enzymes are in saliva?
amylase and lysozyme
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 is the average saliva production?
600-1500 mL/day
What are the three pairs of salivary glands?
parotid, submandibular, sublingual
Which salivary gland is almost completely serous?
parotid (largest gland)
What is the parotid duct called?
stenson’s duct
Where does the parotid gland open?
within the vestibule, opposite upper 2nd molar
What salivary gland has mixed serous and mucous?
submandibular
-inferior and medial to remus of mandible
What is another name for the submandibular duct?
Whartons duct
Where does the submandibular duct open?
at sublingual caruncle
What type of duct are simple cuboidal to columnar epithelium?
striated ducts
Which salivary gland is mostly mucous?
sublingual
What is an acinus?
compound (branched) glands; secretory unit
-can be serous or muscous
What type of cells surround acini and aids in secretion of saliva into ducts?
myoepithelial
What is a sialolith?
salivary stones
What type of saliva are acini?
serous and mucous
What type of ducts are lined by simple cuboidal epithelium and secrete HCO3 and resorb Cl?
intercalated ducts
Serous acini of mixed glands are often in the form of __________
demilunes
What are the functions of salivary glands?
resorb Na, secrete K into saliva, and secrete lysozyme and IgA
