DOH253 Lecture Notes - Lecture 11: Golgi Apparatus, Dental Papilla, Ameloblast
Document Summary
Presecretory stage - all ameloblastic activities before secretion of enamel matrix: differentiation of iee cells. Change from cuboidal to polarised columnar and called preameloblasts. Nucleus near si thus away from basement membrane. Basal lamina marks the future edj: subsequent resorption of basal lamina. Thus future ameloblasts and odontoblasts are in intimate contact allowing inductive signaling to occur. Columnar cells with nucleus toward si away form bm. Future dej and first layers of dentine and enamel forming and dentine is thicker (perhaps two layers since dentine is formed first then enamel and so on) Predentine is the unmineralised part (lighter in colour) Changes of outer mesenchymal cells of dental papilla enamel. Leads to differentiation into odontoblasts at peripheral part of dental papilla cells. First dentine induces the preameloblasts to become ameloblasts and lay down. Terminally differentiated preameloblasts are joined at the sr end by desmosomes forming a proximal (toward enamel organ) terminal web.
