Oral Cavity (7)

Question 1

vestibule

Answer 1

b/t lips/cheeks and teeth to keep stuff in mouth

Question 2

gingivae

Answer 2

aka gums
protect teeth and underlying structures

Question 3

types of oral mucosa

Answer 3

ALL 3 types are stratified squamous epithelium (SSE)
1. lining
2. masticatory
3. specialized

Question 4

lips -skin

Answer 4

keratinized SSE
has hair follicles + sweat + sebaceous glands

exterior boundary

Question 5

lips-lining mucosa

Answer 5

nonkeratinized SSE + subepithelial CT dense irregular
-has labial salivary glands

interior boundary (orbicularis oris muscle b/t skin and lining for closing mouth)

Question 6

lips-vermillion zone

Answer 6

transitional zone @outer corners

keratinized SSE w/ CT papillae + small blood vessels close to surface (red lips)
-no sweat/sebaceous glands

Question 7

lining mucosa

in cavity

Answer 7

basically everywhere - vestubular surface/inside of lip + soft palate + ventral surface tongue + floor mouth + alveoli of gingivae

nonkeratinized SSE overlying dense irregular CT

Question 8

masticatory mucosa

Answer 8

@most regions of gingivae + hard palate (also has mucous glands) + dorsal surface tongue

keratinized SSE (if only partial = perakeratinized)

Question 9

specialized mucosa

Answer 9

@dorsal surface tongue embedded in masticatory mucosa

has papillae (4 types) and taste buds
1.filiform
2.fungiform
3.foliate
4.circumvallate

Question 10

filiform papillae

Answer 10

-smallest and most numerous
-no taste buds
-concial projections of CT for friction for food manipulation

Question 11

fungiform papillae

Answer 11

mushroom shaped
distributed among filiform

have taste buds on dorsal surface

Question 12

foliate papillae

Answer 12

@lateral sides of tongue w/ parallel ridges

taste buds on walls
lingual salivary glands empty into clefts b/t papillae

Question 13

circumvallate papillae

Answer 13

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

Question 14

taste bud structure

Answer 14

taste pore that opens onto epithelial surface so access to tastants

2 cell categories:
1. neuroepithelial
2. basal

Question 15

neuroepithelial cells

taste buds

Answer 15

1. dark
2. light
3. intermediate

apical surface with microvilli
synapse w/ nerves involved with taste

cell types 1-3

Question 16

basal cells

taste buds

Answer 16

stem cells that can dev into light/dark/intermed cells

cell type #4

Question 17

teeth numbers

Answer 17

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

Question 18

teeth tissues

Answer 18

1. enamel
2. dentin
3. cementum

Question 19

enamel

Answer 19

covers anatomical crown (partially submerged)
-hardest substance in body (96% calcium hydroxyapatite)
-not replaced once formed
-vulnerable to acid = cavities (dental caries)

Question 20

enamel structure

Answer 20

columns of enamel prisms

deposition is cyclical
-cross striations = 24 hr development
-retzius lines = stressful events slow deposition

Question 21

cementum

Answer 21

@covers root
attaches to alveolus by periodontal ligament (allows small movement like braces)

50% calcium hydroxyapatite
avascular

Question 22

cells of cementum

Answer 22

1. cementoblasts = secrete cementoid, get incorporated into lacunae as mature
2. cementocytes = lie w/i unconnected lacunae

Question 23

dentin

Answer 23

deep to enamel and cementum
softer than enamel (70% calcium)

produced continuously-grows into pulp cavity with dental tubules that hold extensions of odontoblasts

Question 24

dentin growth lines

Answer 24

1. von ebner lines (circardian, 24 hrs)
2. lines of owen = times of stress like birth

Question 25

odontogenesis

general stages

Answer 25

stages:
1. bud
2. cap
3. bell
4. appositional

Question 26

bud stage

Answer 26

invagination of surface oral ectoderm into mesenchyme

10 lower/upper tooth buds = deciduous teeth

Question 27

cap stage

Answer 27

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

Question 28

bell stage

Answer 28

enamel organ fully forms
1. OEE
2. SR
3. stratum intermedium
4. IEE w/ ameloblasts

dental papilla have odontoblasts + cementoblasts

Question 29

appositional stage

Answer 29

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