Pulp and Pulp Responses Flashcards
3 descriptions of the pulp
- connective tissue
- essentially a matured dental papilla
- dentine is the calcified tissue of the pulp
3 pulpal functions
- dentine formation
- defence and repair
- sensory
similarities of pulp compared to connective tissue
- cells are mainly fibroblasts
- extraceullar matrix of fibrous (collagen) and non-fibrous components
- blood vessels and nerves
- 75% water; 25% organic
differences of pulp compared to connective tissue
- has specialised cells called odontoblasts
- is contained within a rigid chamber
- blood vessels are wide and thin
- densely innervated
Give the 4 pulpal cells
odontoblasts
fibroblasts
stem cells
defence cells
what type of cells are odontoblasts?
specialised ectomensenchymal cells
where are the odontoblast processes found?
in dentine
what do odontoblasts produce upon mild irritation of the pulp?
reactionary tertiary dentine
how is odontoblast activity controlled?
by growth factors
what are the defence cells of the pulp?
macrophages and T-lymphocytes
what can stem cells differentiate into in the pulp?
fibroblasts or odontoblasts
how do number of stem cells in the pulp change with age?
they decline with age
what is the most numerous of pulpal cell types?
fibroblasts
what fibres are and are not seen in the pulp?
collagen fibres are seen
oxytalin fibres are not seen
where does the blood supply terminate in the pulp?
in rich sub-odontoblastic capillary plexus
what do the venules of the pulp not have?
valves
what does stimuli to dentine result in?
pain
increased blood flow
axon reflex –> vasodilation; increased capillary permeability; increased sensitivity
what is the new theory for pulpal death?
due to stasis of blood vessels
what venous structure is classically found in the Cell Free Zone of the pulp?
Plexus of Raschkow
what venous structure is found around odontoblasts?
Marginal Plexus
how does dentinal fluid flow change with pressure?
with pulpal pressure :
inflammation
vasoconstrictors
what are the contents are dentinal fluid?
proteins, glycoproteins and polysaccharides
what percentage of axons that enter a tooth are non-myelinated?
70-80%
what happens to the odontoblasts of the pulp with age?
- 50% have apoptosed
- smaller
- less synthetic organelles
what happens to the fibroblasts of the pulp with age?
less activity
what happens to the pulp with age in terms of vascularity and sensitivity?
decrease in nerve sensitivity and decrease in vascularity
what does calcification of the pulp make?
true pulp stones and false pulp stones
what are true pulp stones?
tubular structure from odontoblast like cells
what are false pulp stones?
calcified fibrous tissue
