Muscle A

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Muscle APPart 1
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Organization

• Cells fibers
• Endomysium
• Fascicle
• Perimysium
• Epimysium
• CT converges to become tendon or aponeurosis
• Fascia

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Picture
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Organization

• Muscles are organs CT, nerves, blood vessels
• Fibers arranged in different ways

sphincter
parallel
convergent
pennate
bipennate
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Attachment

• Most attach to 2 bones
• In general
• Origin - fixed
• Insertion moves

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Muscle Fibers

• Sarcolemma (cell membrane)
• Transverse extensions are T tubules (carry nerve
  impulses deep into cell)
• Sarcoplasm
• Sarcoplasmic reticulum - stores Ca
• Triad

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Muscle Fibers

• Lots of mitochondria, multiple nuclei
• Myofibrils bundles of fibers that fill cell
  (1000)
• Composed of thick and thin microfilaments
  (thousands)

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Striations

• Alternating dark and light bands dues to
  arrangement of thick and thin myofilaments
• A band, I band

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Myofilaments

• Thin filament 3 proteins
• Actin, troponin, tropomyosin
• Thick filament 1 protein
• Myosin

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Picture
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Myofilaments

• Z band/line/disc
• Actin filaments connect here
• Sarcomere
• From z line to z line
• Functional unit of contraction