Lab 8: Digestive system I Flashcards
name main parts of erupted tooth
clinical crown
anatomical crown
root
describe clinical crown (erupted tooth)
enamel
dentin
describe anatomical crown (erupted tooth)
gingiva (cuticle)
mucogingival junction
pulp
odontoblasta
alveolar bone
describe root (erupted tooth)
periodontal ligament
cementum - cementocytes
apical foramen
what must be done for erupted tooth to be sectioned
enamel must be removed to tissue can be sectioned
what is enamel space
space in between dentin and gingiva
describe gingiva
parakeratinized stratified squamous epithelium
describe dentin
70% hydroxyapatite
30% organic material which contains collagen type 1
secreted by odontoblasts as pre dentin (paler than dentin)
describe odontoblasts
columnar cells with processes running in dentin = dentin canaliculi (long processes that run through the dentin as tunnels)
basophilic cytoplasm
nuclei located at base of cell
describe pulp
contains collagen type 1 and 2
fibroblast cells
blood vessels, lymphatics and nerves
lined by odontoblasts
what are sharpeys fibers
insertion of periodontal ligament
where are osteoclasts
in between alveolar bone and periodontal ligament
describe periodontal ligament
dense regular ct
origin in alveolar bone and insertion into cementum (sharpey’s fibers)
describe cementum
thinner
located on side of tooth
acellular
thicker at bottom or root of tooth and can be considered cellular (cementocytes)
play a role in passive eruption
describe mature enamel
99% inorganic material
made of hydroxyapatite crystals
describe immature enamel
70% inorganic material
30% amelogenin
more basophilic than dentin
describe enamel of unerupted tooth
softer
does not need to be removed during prep of slides
describe root sheath
where IDE and ODE come together
separated by stellate reticulum and stratum intermedium
demarcates end of clinical crown and beginning of root sheath
what is pre enamel
THERE IS NO SUCH THING AS PRE ENAMEL
does enamel contain collagen
HECK NO
what is enamel organ
responsible for producing enamel
not present in erupted teeth
name parts of enamel organ
outer dental epithelium (ODE)
stellate reticulum
stratum intermedium
inner dental epithelium (IDE)
describe ODE
Continuous with stratum germinativum of the skin
Squamous cell layer
describe stellate reticulum
wide intercellular spaces are present
largest area of enamel organ
cells here are stellate or star shaped
describe stratum intermedium
resembles stratum spinosum of skin
polygonal shaped cells
1-3 layers of cells
describe IDE
made of ameloblasts
Continuous with stratum germinativum of oral epithelium
cells are columnar and rest on BM
cells have short processes that project into enamel (Tones processes)
describe enamel (of enamel organ)
enamel layer
at bottom
describe tongue
mass of skeletal muscle
covered by oral mucosa
has papillae
what is oral mucosa
non keratinized stratified squamous epithelium
name 3 types of papillae
filiform papilla
fungiform papilla
circumvallate papilla
describe filiform papilla
along midline of tongue
most abundant papilla
shaped like toothpick
nonkeratinized at base but can be keratinized at tip
not involved in taste
describe fungiform papilla
on side and tip of tongue
Mushroom shaped
very few in number
lined by non keratinized stratified squamous epithelium
describe circumvallate papilla
located along lingual V
large and spherical in shape
has a deep groove lined with oral mucosa
taste buds = found in grooves
von ebners gland
describe von ebners glands
serous secretion
secretes lingual lipase
found at base of circumvallate papilla in submucosa
function = to wash particles from taste bud
name 4 main layers of esophagus
mucosa
submucosa
tunica muscularis
adventitia/serosa
describe epithelium of esophagus mucosa
non keratinized stratified squamous epithelium
describe lamina propria of esophagus mucosa
loose irregular ct
contains esophageal cardiac glands (located in upper and lower thirds)
describe muscularis mucosa of esophagus mucosa
thin layer of longitudinally oriented smooth muscle
describe esophagus submucosa
loose irregular ct
esophageal glands proper (mucous glands found throughout)
describe 3 parts of tunica muscularis of esophagus
upper third: skeletal muscle (voluntary)
middle third: skeletal and smooth muscle
lower third: smooth muscle (oblique orientation)
describe adventitia and serosa of esophagus
adventitia = dense irregular ct (present until esophagus traverses the diaphragm)
serosa = thin layer loose ct covered by mesothelium (simple squamous epithelium)
describe parakeratin
not composed of dead cells like keratin layer of skin
appears eosinophilic - not basophilic like that of skin
