Three classes of muscle • Skeletal muscle-responsible for locomotion • Cardiac muscle-responsible for the action of the heart • Smooth muscle-responsible for the contraction of irregular shaped organs such as the intestines.
Skeletal Muscle • Mammal body contains over 400 skeletal muscles • Approx. 40-50% of total body weight
Skeletal Muscle • Functions of skeletal muscle • Force production for locomotion and breathing • Force production for postural support • Heat production during cold stress • Saleable product in livestock producion
Skeletal Muscle • Muscles generally work in pairs to produce movement • One muscle flexes(or contracts) the other relaxes
Structure of Skeletal Muscle:Connective Tissue Covering • Epimysium • Surrounds entire muscle • Perimysium • Surrounds bundles of muscle fibers • Endomysium • Surrounds individual muscle fibers
Structure of Skeletal Muscle:Microstructure • Sarcolemma • Muscle cell membrane • Myofibrils • Threadlike strands within muscle fibers • Actin (thin filament) • Myosin (thick filament)