BIO380H5 Lecture Notes - Lecture 8: Lateral Plate Mesoderm, Paraxial Mesoderm, Cell Cycle
Document Summary
All skeletal muscles derived from the paraxial mesoderm, specifically the somites or somitomeres. Splanchnic mesoderm (lateral plate mesoderm somatic and splanchnic mesoderm) gives rise to muscles of the heart and smooth muscles of the gut and respiratory tracts. Smooth muscle of the blood vessels and the erector pili muscles are derived from local mesenchyme. M-casherin and the ultimate fusing/union of their plasma membranes and become elongated. Satellite cells will divide and give myoblast to fuse with the rest of the cells. Nuclei will be pushed aside, fusion of cytoplasmic membrane to form myotube. Actin, myosin, troponin, and tropomyosin assemble into myofibrils which are called sarcomeres. As myotubes fill with with myofibrils, their nuclei migrate to the periphery of the myotube which is differentiated into a multinucleated muscle fibre which is not able to proliferate. Many signalling pathways will tell somatic epithelium it"s your turn to become muscle cells. Myogenic progenitor cells will express myf-5 very essential for development/assembling.
