口腔组织学分章复习要点（Review of oral tissue credits）.doc

口腔组织学分章复习要点（Review of oral tissue credits） Oral and maxillofacial development There are three stages of human embryo development Period of proliferation: conception --- conception 2W Fertilization, implantation, and formation of the three germ layer Embryo period: 3w---8w Tissue differentiation constitutes an organ and a system The embryo begins to take shape. (facial development) Fetal period: 9w--- was born (palatal development begins in the fetus) neural crest, branchial arch, and pharyngeal pouch Neural crest cells are multipotent stem cells located between the neural tube and the ectoderm, Later, there are two cell cords, which are epithelial mesenchymal transition At 4 weeks, neural crest cells migrate widely and develop into different cells of the body and form many important tissue components, some call it the fourth germ layer. Differentiation of neural crest cells (4W) Develop into a variety of cells, essential for head and neck development: 1, the nervous system tissue: Schwann cells, glossopharyngeal N Festival 2, endocrine tissue: thyroid calcitonin cells, pituitary ACTH and MSH cells. 3, soft and hard connective tissue: facial large connective tissue (external embryo mesenchyme): bone, cartilage, pulp, essence, periodontal membrane. 4, skin tissue: melanocytes, dermis, smooth muscle. The development of branchial arches and pharyngeal pouches 4W Branchial arch: the primitive pharyngeal mesenchyme is rapidly proliferating, forming 6 symmetrical columnar ridges with symmetrical dorsal and ventral directions Between the adjacent branchial arch shallow groove on the surface side of said gills ditch; in the lateral pharyngeal called pharyngeal pouch first pharyngeal ditch and first, second branchial arch abnormalities, congenital preauricular sinus can be formed in front of the tragus: skin narrow blind pipe or pitting. The blind tube continues to extend to the deep cavity and is communicated with the tympanic cavity, which is the pre - auricular fistula Fac