Muscle, muscle tissue tendons Dr. Anna L. Kiss Department of Anatomy, Histology and Embryology Semmelweis University Budapest 2016

General myology Musculature: actíve component of the movement Structure: striated muscle (skeletal) tendons: dense connective tissue connective tissue sheath: fascia (epimysium) Muscle tissues, striated muscle,, contractile proteins, sarcomere

Muscle tissue Smooth muscle Stiated muscle Cardiac muscle Function: contraction Origin: mesoderm Structure: cells or „fibers”

Smooth muscle phylogenetically the most ancient type spindle shaped cells slow, non-synchronized, unvoluntary contraction actin and myosin are NOT arranged in registers internal organs wall

Smooth muscle Nucleus: in the middle of the cells

Smooth muscle thick filaments: myosin thin fialments: actin

Contraction of smooth muscle

Smooth muscle contraction Ca ion: caveolae Ca-binding protein: calmodulin Contractile protein: actin+myosin ATP

Striated(skeletal) muscle

Striated muscle: a.) skeletal b.) visceral c.) cardiac Structure: muscle fibers: multinucleated giant cells (syncitium: fusion of the embryonic myoblasts) lenght: > 30cm diameter: 10-100 µm

Skeletal muscle

Electron Microscopic picture sarcomere

Structural unit of the striated muscle: sarcomera Muscle fibers myofilaments: contractile proteins: actin and myosin regularly arranged cross striation

Sarcomere during contraction

Skeletal muscle

Contractile proteins Myosin head: actin binding site + ATP binding Thin filaments Myosin head: actin binding site + ATP binding thick filaments

Sarcomere

mysosine binding site mysosine head

For the contraction of the skeletal muscle: contractile proteins: actin and myosin Ca2+ (stored in sER) impulse transfer from the sarcoplasm to sER-re (triads) ATP (directly from kreatin phosphate, 20 mmól/kg) mitochondria oxigen (myoglobin + haemoglobin) aerob (biological oxidation) anaerob (fermentation) glikogén

Triád: a.) voltage-gated Ca2+ channels: T-tubules (transverse) SR ciszterna b.) Ca 2+ -ATP-ase Ca 2+ outflow Ca 2+ back to the SER

Types of the skeletal muscle „red” muscle „white” muscle size small large fibers diameter contraction slow fast color dark (red) light (white) numorous few numorous few numorous few fat in the cytoplasm numorous fewer glycogen in the cytoplasm fewer larger amount resistancy bigger smaller

Cardiac muscle

Cardiac muscle cells (bifurcation; X or Y shaped branching cells) cross striation: actin and myosin are in register nucleus is in the middle of the cells intercalated disc (Eberth’s line – junctions) lots of capillaries lipofuscin by aging

Cardiac muscle Intercalated disc: special junctions between cells fast impulse cinduction

Intercalated disc (Eberth’s line) fascia adherens desmosoma gap junction (nexus)

Cardiac muscle

Fine structure of the cardiac muscle diad large amount of mitochondria

impulse condacting cells: Purkinje cells non-differentiated muscle cells!!