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42 Cards in this Set
- Front
- Back
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Muscle hierarchy |
Muscles made up of muscle fibers Muscle fibers made of myofibrils Myofibrils made of thin and thick filaments |
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Line that lacks thick filaments during muscle relaxation |
Z line
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Line that lacks thin microfilaments during muscle relaxation |
M line |
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Sarcomere |
Repeating muscle unit |
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My muscle is striated |
Dark bands are thick filaments Thin bands are thin filaments |
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Filaments during muscle contractions |
Thin and thick microfilaments stay the same length |
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Parts of myosin molecule |
Tail region Head region
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Tail region of myosin |
Adheres to other myosin molecules |
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Head region of myosin |
Binds ATP
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Thin microfilaments |
Made of 2 chains of actin with myosin binding sites |
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Muscle contraction with myosin |
Myosin head binds to actin binding sites and ATP is dephosphorylated Cross-bridge formed ADP + P is released Thin filament moves toward center of sarcomere New ATP binds cross-bridge is broken Repeat |
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Sarcomere at rest |
Tropomyosin covers myosin-binding sites on actin filaments |
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Calcium during muscle contraction |
Increased Calcium present in cytosol Ca binds to troponin Tropomyosin shifts to expose myosin-binding sites on actin |
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Sarcoplasmic reticulum |
Stores calcium in T tubule |
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ACh |
Acetylcholin Binds to specific receptors Causes initiation of action potentials (depolarization) |
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Motor unit |
A single motor neuron and all muscle fibers it controls Each fiber is controlled by only 1 motor neuron |
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Strength of contraction depends on |
Number of units activated |
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Tetanus |
Sustained contraction |
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Tetanus is caused by |
Series of action potentials at high frequency |
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Antagonistic pairs |
Muscles that work together to move body parts back and forth One relaxes while one contracts |
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Types of muscle fibers |
Oxidative fibers Glycolytic fibers Fast-Twitch Slow-Twitch |
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Why oxidative fibers are dark meat |
Has more myoglobin, which is brownish |
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Amount of ATP in aerobic respiration |
30-32 |
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Aerobic respiration |
Uses all steps of glycolysis |
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Metabolism in fast-twitch |
Oxidative or glycolytic |
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Metabolism in slow-twitch |
Only oxidative |
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Mitochondria in slow-oxidative |
Many |
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Mitochondria in fast-oxidative |
Many |
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Mitochondria in fast-glycolytic |
Few |
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Myoglobin content in slow-oxidative |
High |
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Myoglobin content in fast-oxidative |
High |
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Myoglobin content in fast-glycolytic |
Low |
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Contraction velocity in slow-oxidative |
Slow |
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Contraction velocity in fast-oxidative |
Fast |
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Contraction velocity in fast-glycolytic |
Fast |
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Fatigue rate in slow-oxidative |
Slow |
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Fatigue rate in fast-oxidative |
Intermediate |
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Fatigue rate in fast-glycolytic |
Fast |
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Muscle fiber diameter in slow-oxidative |
Small |
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Muscle fiber diameter in fast-oxidative |
Intermediate |
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Muscle fiber diameter in fast-glycolytic |
Large |
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Other types of muscle |
Cardiac Smooth/visceral |
