1. Microscopic Anatomy and Organization of Skeletal Muscle
EX 14
Microscopic Anatomy and Organization of Skeletal Muscle

2. Skeletal Muscle Most numerous Voluntary Striated
Gives you shape, allows for facial expressions, movement, and manipulation

3. Cells of the Skeletal Muscle
Long cylindrical cells called fibers
Multinucleated
Composed of myofibrils
Myofilaments
Made of actin and myosin alternating to produce the banding pattern (I and A bands)
Sacrolema- “plasma membrane”
Sacroplasm- “cytoplasm”

4. Skeletal Muscle Fibers
Figure 10–2a The Formation of a Multinucleate Skeletal Muscle Fiber.
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5. Skeletal Muscle Fibers
Figure 10–2 The Formation of a Multinucleate Skeletal Muscle Fiber.
Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

6. Sarcomeres Contractile units Made up of bundles of myofibrils
Extend from middle of I band to middle of next myofibril

7. Organization of Skeletal Muscle Cells into Muscles
Endomysium – areolar connective tissue sheath that covers muscle fibers
Perimysium – encloses sheathed muscle
Fascicle-bundle of perimysium
Epimysium-bundle of fasciles
Epimysium blend into deep fascia
Fascia blends into tendons

9. Skeletal Muscle Structures
Figure 10–1 The Organization of Skeletal Muscles.
Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

11. Tendons provide durability and conserve space
Provide route of entry for blood vessels

12. Neuromuscular Junction
Junction between a nerve fiber and a muscle cell
Axons stimulate many muscle fibers
Both neuron and muscle fibers make up the motor unit
Neurotransmitters cause a change in Na and K concentration which causes muscle contraction