Muscle 1 - Skeletal Muscle Part 1 1 Skeletal Muscle...

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Unformatted text preview: Skeletal Muscle Part 1 1 Skeletal Muscle Functions n What are the functions of skeletal muscle? Locomotion n Facial expression n Posture n Maintenance of body temperature n 2 Skeletal Muscles n n n Each skeletal muscle is an organ Definition of an organ? What are the tissue types? Skeletal muscle tissue n Connective tissue n 3 Skeletal Muscle Tissue Characteristics n n n Striated Multinucleated Under voluntary control 4 Muscle Structures and their Connective Tissues n Muscle Fiber n n Fassicle n n Surrounded by perimysium Muscle n n Surrounded by endomysium Surrounded by epimysium Tendon 5 Skeletal Muscle Fibers n n Muscle Fiber = elongated, multinucleated muscle cell Myofibril: organelle that makes up muscle fibers 6 Skeletal Muscle Fibers n n Sarcolemma = plasma membrane Sarcoplasmic Reticulum = endoplasmic reticulum endoplasmic n n n Transverse tubules (T-tubules) Terminal cisternae n n Stores calcium Flattened sacs Triad: T-tubule plus 2 terminal cisternae 7 Myofibrils and Sarcomeres n n n Bundles of myofibrils make up muscle fibers Chain of sarcomeres 2 myofilaments of sarcomere n Thin filament n n Actin, troponin, and tropomyosin Thick filament n Myosin 8 Thin Filament Contractile Proteins n Actin n n Tropomyosin n n n Has a binding site for myosin thick filament Rod-like protein Covers the myosin binding sites on actin Troponin n Binds to tropomyosin 9 Thick Filament Contractile Protein n n Myosin Composed of 2 chains twisted together n n Each with a rod-like tail group and a globular head group Head groups attach to actin binding site 10 The Sarcomere n n n n n I bands Z discs A bands H zone M line 11 Exercise 11 n n Only pgs 164 to 166 in 4th ed. Skip the rest of exercise 11 12 Overview of Body Movements n n n n n n n Gliding – flat surfaces glide over each other Flexion - decreases angle of a joint Extension – increase in angle of a joint Abduction – Movement away from midline Adduction – movement toward midline Circumduction – Movement in a circle Rotation – Turn on a pivot with a circle 13 Overview of Body Movements n Special Joint Movements Elevation and depression n Protraction and retraction n Supination and pronation n Inversion and eversion n Dorsiflexion and plantar flexion n 14 Break n n n n Look at anatomy of skeletal muscles Work on pgs 164 to 166 Practice body motions Keep in mind anatomical regions and terminology 15 Exercise 14 16 Muscle Orientation n Origin n n n n “start” of muscle Fixed bone the muscle attaches to Stable Insertion n n n “end” of muscle Attached to another bone (or to skin) Moves toward origin 17 Actions of Muscles n Agonist n n Antagonist n n n Counters effect of agonist Agonist cannot be its own antagonist Synergist n n muscle that causes a specific movement Helps agonist, stabilizes Fixator n Fixes origin 18 Naming Skeletal Muscles n Muscles are named for: Direction of fibers n Size n Location n Shape n Number of origins n Action n 19 Learning Muscle Anatomy n n n n Only responsible for muscles in tables of your required handout First learn the location on the picture or model Then learn the action of the muscle Optional handout on d2l 20 ...
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