Exam 4: GI Tract Flashcards
Gingiva is lined by
masticatory mucosa
Hard palate is lined by
masticatory mucosa (parakeratinized and keratinized epithelium) and submucosa
Burton’s Line
blue-gray ginigval margin - caused by lead poisoning
Most of the oral cavity is lined by
nonkeratinized, stratified sqamous epithelium
3 strata: stratum basale, stratum spinosum, stratum superficiale
Submucosa
Filiform papillae
specialized mucosa associated with tongue
Covers most of tongue surface
Keratinized epithelium
No taste buds
Fungiform papillae
Mushroom shaped
Stratified squamous epithelium
Has taste buds
Circumvallate papillae
Approximate to sulcus terminalis
Largest of papillae
Covered by stratified squamous epithelium
Along lateral margin on either side are taste buds
Deep moat along lateral margin - circle base filled with secretions from serous glands
Foliate papillae
Leek shaped
found on lateral margins of tongue
Contain taste buds in lateral margins
Also have moat and serous glands
Taste bud has 3 cell types
sensory, supporting, and basal
Area of lip facing oral cavity has what kind of epithelium?
lining mucosa (nonkeratinized stratified squamous)
Vermilion zone (red free margin)
transition zone between epidermis of skin (with sebaceous gland and hair follicles) and epithelium of mucosal lining (lamina propria and labial gland is submucosa)
Has no glands or hair follicles
Parotid gland
Only serous cells
Some adipose cells scattered
Submandibular gland
Mixed gland
Primarily serous cells with some mucous cells
Has serous demilunes
Sublingual gland
Mixed gland
Primarily mucous with some serous cells
Has serous demilunes
Anatomic crown of tooth
Enamel and Dentin
Root of tooth
Cementum and dentin
Center of tooth contains
pulp chamber - blood vessels, nerve fibers, connective tissue
Gets smaller as age
Bud stage of tooth development
Process of invagination induced by neural crest cells that made their way into underlying tissue
Cap stage of tooth development
Cells undergo differentiation
Growth of mesenchyme pushes inner enamel epithelium up
Forms dental papilla
Stage induced by Activin Beta-A and BMP 4
Bell stage of tooth development
Inner enamel epithelium bell shaped
4 clearly defined tissue components: outer enamel epithelium, stellate reticulum, stratum intermedium, & inner enamel epithelium
Ameloblasts
Secrete enamel on outer surface of enamel
Derived from oral epithelium of ectoderm
Completely gone when tooth erupts - enamel secretion stops
Odontoblasts
Secrete dentin on pulp cavity side of dentin - whole life
Derived from neural crest cells of neuroectoderm
Appositional stage of tooth development
Dentin and enamel layed down
Bone beginning to form around dental pulp (previous dental papilla)
Cementum
secreted by cementocytes
Avascular
Cellular cementum - lower root, thicker
Attached to bone by Sharpey’s fibers