BIO 3158 Lecture Notes - Lecture 7: Pharyngeal Arch, Dermal Bone, Facial Skeleton
1 Feb 2017
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Document Summary
Chapter 6: evolution of the visceral and cranial skeletons. Chondrocranium: endoskeleton elements (cartilaginous or endochondral) encapsulate the cranium, the nasal region and the inner ear. Spanchonocranium: visceral arches: mandibular, hyoid and branchial arches, underneath the cranium. Dermatocranium: dermal elements that encapsulate the chondrocranum and the splanchocranium, dermal bones the develop directly from mesenchymal cells, and these dermal bones cover pretty much everything in the cranium. The first two arches are normally associated with the jaws and the next five arches are associated with breathing. Visceral arches: branchial arches, arches associated with the jaw. Palatoquadrate: upper jaw, ossification in bony fishes and in terrestrial vertebrates. The structures in the buccal region might look like teeth, but they aren"t and are used in filtering but still no true jaw. At this point all visceral arches are brachial arches and are all involved in breathing.
