ANAT 9999 Lecture Notes - Lecture 11: Sarcomere, Axon, Myocyte
4 Nov 2016
School
Department
Course
Professor
Document Summary
Perimysium- bundles muscles fibers together into fascicles. Sacroplasm- cytoplasm, contains myofibrils, glycogen, and myoglobin. Myoblasts- stem cells that fuse to produce each fiber. Satellite cells- myoblasts that remain unspecialized, regeneration. Sarcoplasmic reticulum- smooth er that forms a network around each fiber, calcium ions, gated in order to release calcium and activate muscle contraction. Transverse (t) tubules- tubular infoldings in sarcolemma, signals sr to release calcium. Triad- t tubule and 2 terminal cisternae. Thick filaments: several hundred molecules of a protein called myosin. Elastic filaments: made of protein called titin, run through core of thick filaments, anchor to z disc and m line, stabilizes thick filaments, prevents overstretching, and helps with recoiling. Myosin and actin are called contractile proteins because they shorten the muscle fiber. Tropomyosin and troponin are called regulatory proteins because they determine when to contract. When thin filaments move, they pull on this, which pulls connective tissues and the links actin to peripheral protein tendon.
