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Thursday October 22, 2009. Pick up the muscle note sheet! Did you miss the test on Tuesday? Did you complete virtual surgery? COOL!. The Man Whose Arms Exploded. Agenda & Homework. Agenda: 1) Cadaver visits December 8 & 10, 2009 Muscle Physiology Muscle Anatomy. Homework:
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Thursday October 22, 2009 • Pick up the muscle note sheet! • Did you miss the test on Tuesday? • Did you complete virtual surgery? COOL! The Man Whose Arms Exploded
Agenda & Homework Agenda: 1) Cadaver visits December 8 & 10, 2009 • Muscle Physiology • Muscle Anatomy Homework: Learning muscles by making flash cards Use the website to study muscles
Muscle Overview • The three types of muscle tissue are skeletal, cardiac, and smooth • These types differ in structure, location, function, and means of activation
Muscle Tissue: Cardiac Figure 4.11b
Muscle Tissue: Smooth Figure 4.11c
Muscle Tissue: Skeletal • Long, cylindrical, multinucleate cells with obvious striations • Initiates and controls voluntary movement • Found in skeletal muscles that attach to bones or skin
Muscle Tissue: Skeletal Figure 4.11a
Skeletal Muscle Tissue • Packaged in skeletal muscles that attach to and cover the bony skeleton • Has obvious stripes called striations • Is controlled voluntarily (i.e., by conscious control) • Contracts rapidly but tires easily • Is responsible for overall body motility • Is extremely adaptable and can exert forces ranging from a fraction of an ounce to over 70 pounds
Skeletal Muscle • Skeletal muscle cells are elongated and are called muscle fibers • Muscle contraction depends on two kinds of myofilaments (proteins) – actin and myosin • Muscle terminology • Sarcolemma – muscle cell membrane • Sarcoplasm – cytoplasm of a muscle cell • Prefixes – myo, mys, and sarco all refer to muscle
Muscle Function 1) Skeletal muscles are responsible for all locomotion 2) Muscles also maintain posture, stabilize joints, and generate heat (ex: shiver)
Skeletal Muscle • Each muscle is a discrete organ composed of muscle tissue, blood vessels, nerve fibers, and connective tissue
Skeletal Muscle • The three connective tissue sheaths are: • Endomysium – fine sheath of connective tissue composed of reticular fibers surrounding each muscle fiber (cell) • Perimysium – fibrous connective tissue that surrounds groups of muscle fibers called fascicles • Epimysium – an overcoat of dense regular connective tissue that surrounds the entire muscle
Skeletal Muscle Circle the Endomysium, Perimysium & Epimysium Figure 9.2a
Nerve and Blood Supply • Each muscle is served by one nerve, an artery, and one or more veins • Each skeletal muscle fiber is supplied with a nerve ending that controls contraction • Contracting fibers require continuous delivery of oxygen and nutrients via arteries • Wastes must be removed via veins
Skeletal Muscle: Attachments • Muscles attach: • Directly – epimysium of the muscle is fused to the periosteum of a bone 2. Indirectly – connective tissue wrappings extend beyond the muscle as a tendon or aponeurosis