e06.Muscular Tissue肌组织.ppt

组织胚胎学课件 七年制英文医学班专用 Chapter 6  Muscular Tissue 1.?????? General description 1) components: ---cell: muscle fiber-myofiber elongated thread-liked Sarcolemma Sarcoplasm sarcoplasmic reticulum: SER ---extracellular G.S: CT with BV, LV and N 2) classification According to the structure and function skeletal muscle: striated, voluntary cardiac muscle: striated, involuntary smooth muscle: unstriated, involuntary 2.????Skeletal muscle Muscle is an organ, consists of muscle fiber and CT, fixed on bone by tendons CT: epimysium: DCT Perimysium Endomysium muscle satellite cell: differentiate and proliferate function: supporting, connecting, nourishing and regulating 1)????? microstructure of skeletal muscle fiber ① long cylindrical 10-100um in diameter,1-40mm long ② multinucleate, nuclei are ovoid, distributed under sarcolemma ③ filled with longitudinal parallel-arranged myofibrils myofibril: 1-2um in diameter cross striation: light band -I(isotropic) band, dark band- A(anisotropic) band --A band: M-line, H-band --I band: Z-line * sacromere: a segment of myfibril extending from one Z line to next Z line, which is composed of 1/2 I band, A band and 1/2 I band ,is the smallest structural and functional unit of myofibril 2)?Ultrastructure of myofiber ①???? myofibril: composed of ---thick myofilament: 1.5 um long, 15nm in diameter composed of myosin: -rob: in bundles -head: cross bridge- binding site(ATPase activity) ---thin myofilament: 1um long, 5nm in diameter composed of: A. actin- spherical monomers of globular-actin arranged in two row and twisted- filamentous actin, each monomer has binding site B.tropomyosin: filamentous protein of two polypeptide chains C. troponin: three sub-units: -Tn T: bind to tropomyosin -Tn C: binds to calcium ions -Tn I: inhibite acti