BIOB33H3 Lecture Notes - Lecture 4: Epiphyseal Plate, Clastic Rock, Pubic Symphysis
Document Summary
Neurulation - process of nervous system formation from ectoderm. Neurulation starts with signals sent out by notochord: Notochord extends down the midline from the mesoderm. Tube the 2 sides come together eventually at the top, forming the neural tube, the ectodermal layer grows over the tube and completely closes it. Eventually the neural tube runs the length of the embryo note: spinabifida is the failure of the tube to close, skin (ectoderm) doesn"t grow over the neural tube and it is exposed to the environment. Mesoderm subdivides into: notochord - basis for central body axis and axial skeleton, induction of neural tube, paraxial mesoderm - on both sides of neural tube forms somites, block-like masses responsible for. Endoderm - inner-most tissue after embryonic folding forms lining of digestive, respiratory and urinary tracts, thyroid gland, parathyroid gland, thymus, liver, gallbladder and pancreas. Most diverse, abundant, widely distributed and microscopically variable.