BIO 357 Lecture Notes - Lecture 6: Odontoblast, Neural Crest, Dentin
Document Summary
These tissues support the body against gravity and other forces. They are also used to store calcium and to provide places for muscle attachment. It is found on the outside of the teeth. This is important on hard teeth that are used for chewing. Some mammals chew on bones, so it is important that the teeth are harder than the bones that they chew. Ameloblasts secrete the enamel and then move away from where they initially secreted it. This is the second hardest tissue of the body. It comes from the dermis- papillary layer and is formed by neural crest cells. Odontoblasts secrete the dentin and then move away. This tissue is internal to enamel, external to bone. Dentin is porous and there are nerves within it. Comes from the dermis- from mesenchymal stem cells specifically. The above percentages vary depending on the location of the bone within the body and depending on the species the bone is coming from.
