BIO 3158 Lecture Notes - Lecture 3: Patella, Medullary Cavity, Bone
16 Jan 2017
School
Department
Course
Professor
Document Summary
Large vacuolated cells within a sheath of fibrous connective tissues. Ancestral structure observed in larval tunicates and amphioxus (cephalochordates) Contractions are alternating, and this will be the main mode of locomotion for most fish. The structure is observed in larval stages and in tunicates. Found in adults of several groups of sarcopterygians (lobe-fined) fishes (coelacanth) and in primitive amphibians. Notochord is replaced by a spinal cord. Typically found in all chordates, mainly in the larval stage, but two still have it in the adult stage. In more vertebrates the notochord is replaced by the centrum of the vertebra and other vertebral elements. Often the vertebral column has replaced the notochord by 7 weeks in humans. In humans the notochord exists as the intervertebral discs as the nucleus pulposus. Loose connective tissues: mesenchymatous tissue --> fibroblasts. Collagen fibers (weak elasticity and high flexibility) The concentration of fibers will depend on the tissue type.
