Histology of Pulp Flashcards
describe odontoblasts
location
Cells of the Pulp
- FULLY DIFFERENTITATED
- no cpacity to regenerate
- DENTINOGENESIS
- type I collagen
- ground substance
- hydroxyapatite crystals
have odontoblastic processes that extend into the dentinal tubules
most numerous cell type in the pulp?
fibroblasts
- production and degraation of collagen and ground substance
- relatively undifferentiated cell
fibrocytes
mature fibroblasts in the pulp
number increases with pulpal maturity
maintenance of collagen
histiocytes?
fixed macrophages in the pulp
‘mononuclear phagocytic system’
Class II antigen presenting cells where?
odontoblastic layer
mast cells?
cells of the pulp
- source of histamine
may/may not be present in ‘non- inflamed pulp’
describe ground substance of the pulp
sol- gel colloidal system
proteoglycans and water
matrix for connective tissue cells and collagen
Affarent nerve fibers
regarldess of stimulus interprit them as PAIN
Important
what stimulates the myelinated a -delta fibers
EPT and cold tests
Important
what stimulates the myelinated a -delta fibers
EPT and cold tests
Brannstrom’s hydrodynamic theory
the rapid movement of dentinal fluid in the dentinal tubules stimulates teh A-DELTA nerve fibers located in the odontoblastic layer of the pulp
*MECHANO-STIMULATION
dentinal tubules funtion as capillary tubules?
YES – associated with brannstrom’s hydrodynamic theory of pain
For
- heat
- cold
- dehydration
- probing with an explorer
brannstrom’s hydrodynamic theory of pain associated with C fibers?
NO– pain does NOT LINGER
- if stop stimulus it stops
pulp tissue is NOT IRREVERSIBLY DAMAGED
- explains the hypersensitive dentin
describe deep pulpal pain
Pulpal inflammation
theory where C fibers are triggered
“modulated theory”
algogenic substances
released by inflammatory cells in the pulp and create an environment where promotes stimulation of C- fibers because the environment of the inflammation
- lowers the threshold for the C fibebrs
modulation theory?
associated with algogenic substances released
released by inflammatory cells in the pulp and create an environment where promotes stimulation of C- fibers because the environment of the inflammation
T/F propriception occurs in the pulp?
FALSE – NO PROPRIOCEPTIVE fibers in the pulp
they are found in the PDL
‘localization of pain’
describe capillaries
plexus?
fenestrated
cell free zone
‘subodontoblastic plexus’
venules collapse?
true
- collapse when subjected to increase in pulpal interstitial pressure
higher chance of collapsing if more pressure
arteriovenous anastomoses imortance?
avoiding capillary bed during inflammtion
becomes a shunting system
direct communication betweeen arterioles and venules *
regulation of pulpal blood flow
developmental dentin aka
primary includes - orthodentin -mantle -pre dentin - circumpulpal (below mantle)
SA and number of tubules at DEJ vs pulp
less at DEJ and more closer to pulp
functions of dentin
dentinogenesis
nutrition
neural
defense
describe odontoblastic layer
a morphologic zone that is one cell layer thick with capillaries and nerve endings
desomosome lie junctions
cell poor zone vs cell rich zone
poor = plexus of capillaries and unmyleniated nerve fibers
rich = fibroblasts and undifferentiated mesechymal cells
pulp proper
core of CT tissue (collagen and ground substance)
nerve and blood vessels
fibroblasts . macrophages/ lymphocytes/ plasma cells
undifferntitated mesenchymal cells in the pulp
stem cells (PLURIPOTENTIAL)
CELL rich zone
source of odontoblasts
relationship between fiber number within pulp and age of patients
number of fibers INCREASES with age of the pulp
a fibers are where usually
central area of the pulp
when are A fibers formed?
not fully formed until 5 years after eruption
neural pathway of A delta myleniated located where
plexus of raschkow
cell free zone
odontoblastic layer
predentin/ dentin
neural pathway of C umyleniated located where
within A delta fiber bundles throughout body of the pulp – so same way the a do from plexus – cell free zone – odontoblastic layer – predentin – dentin
CHOLINERGIC PARASYMPATHETIC nerve fibers in the pulp?
NO have not been fouond – so no neural vasodilatory control of blood vessels within th epulp
efferent nerve fibers of pulp
function in vasoconstriction and dentinogenesis
four theories of pulpal stimulation
- direct
- transduction
- hydrodynamic
- modulation
endo focuses on the hydrodynamic one and modulation
arterioles within the pulp
no neural vasodilatory control
vasoCONSTRICTION controlled by post-ganglionic sympathetic nerve fibers
