组织胚胎学课件 第六章 肌组织

2) classification According to the structure and function skeletal muscle: striated, voluntary cardiac muscle: striated, involuntary smooth muscle: unstriated, involuntary
④ Mitochondria, glycogen, lipid droplet
3) Sliding filament hypothesis
B.tropomyosin: filamentous protein of two polypeptide chains C. troponin: three subunits: -Tn T: bind to tropomyosin -Tn C: binds to calcium ions -Tn I: inhibite actinmyosin interaction
③
Sarcoplasmic reticulum:
---definition: A longitudinal distributed tubular system formed by smooth endoplasmic reticulum ---structure: H-A band: longitudinal enclose myofibril-longitudinal tubule A-I junction: enlarge to form flattened sac— terminal cisternae * triad: one T-tubule +two terminal cisternae ---function: there are calcium pump proteins (ATPase) on membrane, so it can store and release calcium ions
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
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
组织胚胎学课件
七年制英文医学班专用
中国医科大学
基础医学院
组胚—英文教学组
Muscular Tissue
Chapter 6
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
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
---thin myofilament: 1um long, 5nm in diameter composed of: A. actinspherical monomers of globularactin arranged in two row and twisted- filamentous actin, each monomer has binding site
2) Ultrastructure of myofiber
ຫໍສະໝຸດ Baidu
① myofibril: composed of ---thick myofilament: 1.5 um long, 15nm in diameter composed of myosin: -rob: in bundles -head: cross bridgebinding site(ATPase activity)
② Transverse tubule (T tubule): ---definition: sarcolemma and basement membrane invaginate into sarcoplasm to form a transverse distributed tubular system ---location: A-I junctional part ---function: transfer the information into cytoplasm