BIO354H5 Lecture Notes - Lecture 7: Mandible, Skull Roof, Facial Skeleton
Document Summary
Not all bone is made from the same source material. Dermal, epidermal, & mesodermal (endochondral) sources contribute to various forms of bone. These are more often generated by mesodermal derivatives. The ones laid out in the beginning which are then replaced by bone. The dermal element, laid out by bone (many tissues) or ectodermal elements which lay out cartilage first then are replaced by bones. These are the most common means of forming the skeletal system. There are 2 competing theories on how the jaw is formed - whether formed from combination the cardiac and cascet - or just from one. A lot of challenges that come to naming is that it was named pre-scientific era. Limited to knowledge and equipment to understand knowledge. Effort to change systematic language is not current importance. Skull bones in fish - primary sources of bones in skull of a fish. Yellow is splanchnocranium, blue is chondrocranium and pink is dermatocranium.
