Histology of Pulp

Question 1

describe odontoblasts

location

Answer 1

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

Question 2

most numerous cell type in the pulp?

Answer 2

fibroblasts

• production and degraation of collagen and ground substance
• relatively undifferentiated cell

Question 3

fibrocytes

Answer 3

mature fibroblasts in the pulp

number increases with pulpal maturity

maintenance of collagen

Question 4

histiocytes?

Answer 4

fixed macrophages in the pulp

‘mononuclear phagocytic system’

Question 5

Class II antigen presenting cells where?

Answer 5

odontoblastic layer

Question 6

mast cells?

Answer 6

cells of the pulp
- source of histamine

may/may not be present in ‘non- inflamed pulp’

Question 7

describe ground substance of the pulp

Answer 7

sol- gel colloidal system

proteoglycans and water

matrix for connective tissue cells and collagen

Question 8

Affarent nerve fibers

Answer 8

regarldess of stimulus interprit them as PAIN

Question 9

Important

what stimulates the myelinated a -delta fibers

Answer 9

EPT and cold tests

Question 10

Important

what stimulates the myelinated a -delta fibers

Answer 10

EPT and cold tests

Question 11

Brannstrom’s hydrodynamic theory

Answer 11

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

Question 12

dentinal tubules funtion as capillary tubules?

Answer 12

YES – associated with brannstrom’s hydrodynamic theory of pain

For

• heat
• cold
• dehydration
• probing with an explorer

Question 13

brannstrom’s hydrodynamic theory of pain associated with C fibers?

Answer 13

NO– pain does NOT LINGER
- if stop stimulus it stops

pulp tissue is NOT IRREVERSIBLY DAMAGED
- explains the hypersensitive dentin

Question 14

describe deep pulpal pain

Answer 14

Pulpal inflammation

theory where C fibers are triggered

“modulated theory”

Question 15

algogenic substances

Answer 15

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

Question 16

modulation theory?

Answer 16

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

Question 17

T/F propriception occurs in the pulp?

Answer 17

FALSE – NO PROPRIOCEPTIVE fibers in the pulp

they are found in the PDL

‘localization of pain’

Question 18

describe capillaries

plexus?

Answer 18

fenestrated

cell free zone

‘subodontoblastic plexus’

Question 19

venules collapse?

Answer 19

true
- collapse when subjected to increase in pulpal interstitial pressure

higher chance of collapsing if more pressure

Question 20

arteriovenous anastomoses imortance?

Answer 20

avoiding capillary bed during inflammtion

becomes a shunting system

direct communication betweeen arterioles and venules *

regulation of pulpal blood flow

Question 21

developmental dentin aka

Answer 21

primary 
includes 
- orthodentin 
-mantle
-pre dentin 
- circumpulpal (below mantle)

Question 22

SA and number of tubules at DEJ vs pulp

Answer 22

less at DEJ and more closer to pulp

Question 23

functions of dentin

Answer 23

dentinogenesis

nutrition

neural

defense

Question 24

describe odontoblastic layer

Answer 24

a morphologic zone that is one cell layer thick with capillaries and nerve endings

desomosome lie junctions

Question 25

cell poor zone vs cell rich zone

Answer 25

poor = plexus of capillaries and unmyleniated nerve fibers

rich = fibroblasts and undifferentiated mesechymal cells

Question 26

pulp proper

Answer 26

core of CT tissue (collagen and ground substance)

nerve and blood vessels

fibroblasts . macrophages/ lymphocytes/ plasma cells

Question 27

undifferntitated mesenchymal cells in the pulp

Answer 27

stem cells (PLURIPOTENTIAL)

CELL rich zone

source of odontoblasts

Question 28

relationship between fiber number within pulp and age of patients

Answer 28

number of fibers INCREASES with age of the pulp

Question 29

a fibers are where usually

Answer 29

central area of the pulp

Question 30

when are A fibers formed?

Answer 30

not fully formed until 5 years after eruption

Question 31

neural pathway of A delta myleniated located where

Answer 31

plexus of raschkow

cell free zone

odontoblastic layer

predentin/ dentin

Question 32

neural pathway of C umyleniated located where

Answer 32

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

Question 33

CHOLINERGIC PARASYMPATHETIC nerve fibers in the pulp?

Answer 33

NO have not been fouond – so no neural vasodilatory control of blood vessels within th epulp

Question 34

efferent nerve fibers of pulp

Answer 34

function in vasoconstriction and dentinogenesis

Question 35

four theories of pulpal stimulation

Answer 35

1. direct
2. transduction
3. hydrodynamic
4. modulation

endo focuses on the hydrodynamic one and modulation

Question 36

arterioles within the pulp

Answer 36

no neural vasodilatory control

vasoCONSTRICTION controlled by post-ganglionic sympathetic nerve fibers