Development of Enamel Flashcards
What causes the organelles to move to the opposite end of each preameloblast?
A polarity change
Why does a polarity change occur in preameloblasts?
Isolation from nutrients
What happens when a polarity change occurs in preameloblasts?
- Organelles move to the opposite end of each cell
- Preameloblasts are now called ameloblasts
What are ameloblasts?
Enamel forming cells
Where do ameloblasts arise from?
The oral ectoderm
What are enamel-forming cells called?
Ameloblasts
When the ameloblasts begin to lay down an enamel matrix, what is formed?
DEJ
When is the DEJ formed?
When ameloblasts begin to lay down an enamel matrix
When an enamel matrix is laid down, what structure is formed?
DEJ
What do ameloblasts do during calcification?
Travel to the surface depositing crystals onto the matrix
Which cells deposit crystals onto the enamel matrix during calcification?
Ameloblasts
Calcification, aka
Deposition
What do ameloblasts lay down at the end of the bell stage?
An inorganic/organic matrix
When do ameloblasts lay down an inorganic/organic matrix?
At the end of the bell stage
What are the two stages of calcification?
Mineralization Stage
Maturation Stage
What is the Mineralization Stage?
One stage of calcification, all crystals have been laid down and will never increase in number
What is the Maturation Stage?
One stage of calcification, crystals grow and become tightly packed against one another
What happens to the stratum intermedium and stellate reticulum?
Broken down by ameloblasts as ameloblasts approach the surface
When do ameloblasts stop making enamel?
When they meet the OEE cells
What happens when the ameloblasts meet the OEE cells?
They stop making enamel
What is Nasmyth’s Membrane?
Protective layer over the enamel, laid down by ameloblasts
When is Nasmyth’s Membrane produced?
After ameloblasts meet the OEE cells and have stopped making enamel
What is the Reduced Enamel Epithelium?
Layer formed by ameloblasts flattening out and blending with OEE cells
Ameloblasts flatten out and blend with OEE cells to form what?
Reduced Enamel Epithelium
What is the function of Reduced Enamel Epithelium?
Secrete glue called epithelial attachment that holds gingiva to the tooth
What is epithelial attachment?
Secretion of the REE that holds gingiva to the tooth
What eventually happens to REE?
It is worn away naturally
