Amelogenesis Flashcards
What is amelogenesis
the process of the formation of enamel
It starts with..
followeded by….
ameloblst laying down enamel matrix and protein
mineralisation
organic matrix contists of
which are mainly
called
organic material
2 proteins
Amelogenins and non-amelogenins
non-amelogenins proteins consist of
Enamelin
Tuftelin
Ameloblastin
what is the ratio of proteins in amelogenins and non-amelogenins
90% Amelogenins
10% non-amelogenins
once enamel is fully formed enamel proteins make up …% of enamel
4
inorganic portion of enamel of composed of
hydroxyapetite
Amelogenesis is divided into 3 stages:
pre secretory
secretory
maturation
what happens in the presecretory stage
inner enamel epithelium differitate into ameloblast
what happens at the secrectory stage
ameloblasts secrect enamel matrix/proteins forming the enitire enamel thickness
what happens at the maturation
Ameloblast carry out activities that help, degradation of enamel matrix and placement of minerals/inorganic material
preesecretory stage is further divided into 2 stages
morphogenetic phase/ differentiation phase
The morphogenetic phase occurs….. stage of tooth development, when…
IEE are…..
Organelle facts….
bell, shape of crown is established
low columnar/cuboidal
central nucelous/ golgi apparatus located at proximal part of cell (towards stratum intermedium)
other organelles are scattered
What happens during differentitaion phase…
What happens to the cell
Organells of the cells
IEE become ameloblast
elongates and becomes tall and columnar
nucelus shifts proximal (towards stratum intermedium)
Golig complex shifts distal (towards dental papilla)
mitochrondia which was scattered clusters proximally
What happens when IEE is going through changes??
While the changes is happening there are symentiously changes to the dental papilla cells, to change into odontoblasts, these send signalling molecules to the differentiated ameloblast. Odontoblast start to lay dentine at the end of the differentiation phase
Ameloblast are attched to each other with the help of
located…
junctional complex
proximally and distally
once the pre lyer of dentiin is formed..
T/F dentine is needed for enamel formation
it stimulates the ameloblasts to begin enmel formation
True just like the IEE helps in the diffention of dental papilla cells into odontoblasts, the inital layer of dentin is needed to stimulate ameloblast to lay down the enamel matrix
in the secretory stage ameloblasts develop a ….. called the……..
Once fully devleoped it is a ………
consisting of a …..
Intialy ameloblasts only have
structure / tomes process
distal extension
proximal and distal portion
proximal tomes
in the secretory stage ribosomes help
which are packeages into
These contain
and are then secrected via
the inital layer is laid down on the..
and is minerlised
meaning that this layer of enamel does not contain
synthesis proteins
secrectory granules in the Golgicomplex
enamel proteins
tomes process
mantel dentin (initial dentin)
immediately
enamel rods
As more enamel matrix is layed down ameloblasts move
The tomes process develops
This extention is….
and it keeps…
The tomes process resposible for
Away from the enamel
And extention from the proximal portion
distal tomes process
elongating as more enamel matrix is secrected
Rod and interrod enamel
enamel matrix is sectrected from two sites of the tomes process
The enamel matrix sectrected by the proximal portion……. the enamel matrix sectrected by the distal portion of the tomes process
The enamel matrix secrected by the distal of the tomes process forms
That which surrounds the rod is called
as the enamel matrix contiues to be sectrected , the distal portion of the tomes process…..but gradually becomes….and get ….. out of existance
Once this happens there is a thin space at this junction between the….. filed with
the proximal portion of the tomes process and the distal portion of the tomes process
surrounds/ encircles
Enamel rod
Interrod enamel
Elongates/ thinner/ squeezed
Rod and interod / inorganic material
The distal portion of the tomes process helps form….
Once the tomes process has disappeared the ameloblasts
meaning the last bit of enamel formed has
So the final enamel is composed of
enamel sheath between the enal rods and interenamel rods
assembles how it was initally
No enamel rods
enamel with rods and interods squeezed between two layers of enamel without rods
Maturation phase of amelogenesis consitis of
Transitionl phase and mauration prop
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