Oral Cavity (7) Flashcards
vestibule
b/t lips/cheeks and teeth to keep stuff in mouth
gingivae
aka gums
protect teeth and underlying structures
types of oral mucosa
ALL 3 types are stratified squamous epithelium (SSE)
1. lining
2. masticatory
3. specialized
lips -skin
keratinized SSE
has hair follicles + sweat + sebaceous glands
exterior boundary
lips-lining mucosa
nonkeratinized SSE + subepithelial CT dense irregular
-has labial salivary glands
interior boundary (orbicularis oris muscle b/t skin and lining for closing mouth)
lips-vermillion zone
transitional zone @outer corners
keratinized SSE w/ CT papillae + small blood vessels close to surface (red lips)
-no sweat/sebaceous glands
lining mucosa
in cavity
basically everywhere - vestubular surface/inside of lip + soft palate + ventral surface tongue + floor mouth + alveoli of gingivae
nonkeratinized SSE overlying dense irregular CT
masticatory mucosa
@most regions of gingivae + hard palate (also has mucous glands) + dorsal surface tongue
keratinized SSE (if only partial = perakeratinized)
specialized mucosa
@dorsal surface tongue embedded in masticatory mucosa
has papillae (4 types) and taste buds
1.filiform
2.fungiform
3.foliate
4.circumvallate
filiform papillae
-smallest and most numerous
-no taste buds
-concial projections of CT for friction for food manipulation
fungiform papillae
mushroom shaped
distributed among filiform
have taste buds on dorsal surface
foliate papillae
@lateral sides of tongue w/ parallel ridges
taste buds on walls
lingual salivary glands empty into clefts b/t papillae
circumvallate papillae
8-12 large pap anterior to sulcus terminalis and surrounded by deep groove
taste buds on sides of papillae
lingual salivary glands empty into grooves
taste bud structure
taste pore that opens onto epithelial surface so access to tastants
2 cell categories:
1. neuroepithelial
2. basal
neuroepithelial cells
taste buds
- dark
- light
- intermediate
apical surface with microvilli
synapse w/ nerves involved with taste
cell types 1-3
basal cells
taste buds
stem cells that can dev into light/dark/intermed cells
cell type #4
teeth numbers
permanent = 32 (8 p/quadrant)
-molars only erupt once
deciduous/primary = 20 (5/quadrant)
- will lose and be replaced, tooth fairy
- 2 incisor + 1 canine + 2 premolar
teeth tissues
- enamel
- dentin
- cementum
enamel
covers anatomical crown (partially submerged)
-hardest substance in body (96% calcium hydroxyapatite)
-not replaced once formed
-vulnerable to acid = cavities (dental caries)
enamel structure
columns of enamel prisms
deposition is cyclical
-cross striations = 24 hr development
-retzius lines = stressful events slow deposition
cementum
@covers root
attaches to alveolus by periodontal ligament (allows small movement like braces)
50% calcium hydroxyapatite
avascular
cells of cementum
- cementoblasts = secrete cementoid, get incorporated into lacunae as mature
- cementocytes = lie w/i unconnected lacunae
dentin
deep to enamel and cementum
softer than enamel (70% calcium)
produced continuously-grows into pulp cavity with dental tubules that hold extensions of odontoblasts
dentin growth lines
- von ebner lines (circardian, 24 hrs)
- lines of owen = times of stress like birth
odontogenesis
general stages
stages:
1. bud
2. cap
3. bell
4. appositional
bud stage
invagination of surface oral ectoderm into mesenchyme
10 lower/upper tooth buds = deciduous teeth
cap stage
formation of enamel organ with
1. outer enamel epithelium (OEE)
2. stellate reticulum (SR)
3. inner enamel epithelium (IEE)
also dental papilla from neural crest cells form
bell stage
enamel organ fully forms
1. OEE
2. SR
3. stratum intermedium
4. IEE w/ ameloblasts
dental papilla have odontoblasts + cementoblasts
appositional stage
formation of tooth crown (before the root)
dentin (secreted 1) and enamel secreted (on top of dentin)
ameloblasts remove organic material + minerals to harden enamel then degenerate in eruption
root forms during eruption
