1 / 16

Muscle Tissue

Muscle Tissue. Functions : movement change size and shape of organs Myofilament : thin filament : actin thick filament : myosin. Classification of Muscle. Striated muscle : skeletal muscle : attached to bone visceral striated muscle restricted to soft tissues cardiac muscle :

geordi
Download Presentation

Muscle Tissue

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Muscle Tissue • Functions : • movement • change size and shape of organs • Myofilament : • thin filament : actin • thick filament : myosin

  2. Classification of Muscle • Striated muscle : • skeletal muscle : • attached to bone • visceral striated muscle • restricted to soft tissues • cardiac muscle : • muscle of heart • Smooth muscle : • viscera and vascular system

  3. Skeletal Muscle • Muscle fiber : • fusion of myoblasts • multinucleated cylindrical fiber • sarcolemma : • basal lamina, external lamina, reticular lamina • Connective tissue : • endomysium : reticular fiber surround muscle fiber • perimysium : fascicle • epimysium : dense connective tissue

  4. Skeletal Muscle Types • Red fibers : • slow-twitch motor unit • long, slow contractions, maintain erect posture • White fibers : • fast-twitch motor unit • rapid contractions, fine movements • Intermediate fibers : • Myoglobin : oxygen-binding protein

  5. Myofibrils and Myofilaments • Myofibril : structural and functional subunit • Sarcoplasmic reticulum : sER of muscle • Cross-striations : • A band • H zone • M line • I band • Z line ( Z disc ) • Sarcomere : the basic contractile unit

  6. Myofilaments Arrangement • Thin filaments : • actin : tropomysin, troponin • a-actinin : anchor thin filament at Z disc • nebulin : anchor thin filament at Z disc • Thick filament : • myosin • myomesin : hold myosin filaments • C protein : hold myosin filaments • Titin :elastic protein

  7. Actin Structures • Actin : • F-actin (filamentous actin) • tropomyosin • troponin complex: • torponin-T (TnT) : binds to tropomyosin • torponin-C (TnC) : bind calcium • torponin-I (TnI) : inhibit actinmyosin interaction • G-actin (globular actin)

  8. Myosin Structures • Myosin : • two polypeptide chains double helix • tail to tail • structures • tail • globular head : (cross bridge) • ATP-binding site • ATPase

  9. Regulation of Contraction • Triad : at A band end terminals • Transverse tubular system : • plasma membrane invaginations • membrane depolarization • Terminal cisterna : • sarcoplasmic reticulum • calcium storage and release

  10. Motor Innervation • Motor unit : • Motor neurons • myelin sheath : • Schwann cell (neurilemmal cell), teloglia • motor end plates : • junctional folds • all muscle fiber innervated by single motor nerons • Atrophy :

  11. Sensory Innervation and Repair • Neuromuscular spindle : • modified muscle and capsule • nuclear bag fiber • nuclear chain fiber • primary afferent fibers • g efferent fibers • Tendon organs : • Repair : satellite cells

  12. Cardiac Muscle • Nucleus : • central location • Cross-striation : • like skeletal muscle • Intercalated discs : • fasciae adherentes • maculae adherentes • gap junctions • Branch :

  13. Contraction of Cardiac muscle • Diad : at Z disc • T tubule • terminal cisternae ( sER ) • Spontaneous rhythmic contraction • Cardiac conducting cells (Purkinje cells) • Nervous innervation : modify the rate of contraction • Injury repair by fibrous connective tissue

  14. Smooth Muscle • Fusiform cell • Single center nucleus • Myofilaments : cytoplasmic densities • actin • myosin • dense bodies (similar to Z disc of striated muscle) • No T system

  15. Contraction and Control • Spontaneous contractile activity • Regulatory control : • autonomic nervous system : • sympathetic nerves • parasympathetic nerves • hormones : • oxytocin • no motor end plate formation

  16. Secretion, Repair, and Differentiation • Secretion : • fibers : collagen, reticular, elastin, proteoglycans • hormone : renin • Smooth muscle renew, repair, and differentiation : • undifferentiated mesenchymal cells • pericytes (vessels) • smooth muscle mitosis • myofibroblast • myoepithelial cells (myoid cell)

More Related