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13 Cards in this Set
- Front
- Back
Skeletal Muscle |
Responsible for voluntary movement and is therefore innervated by somatic nervous system. |
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Red Fibers |
Slow-twitch fibers of skeletal muscle that have high myoglobin content and derive energy aerobically, and lots of mitochondria. |
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White Fibers |
Fast-twitch fibers that contain much less myoglobin. |
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Smooth Muscle |
Responsible for involuntary actions, controlled by autonomic nervous system. Can contract without nervous input (myogenic activity). |
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Tonus |
Sustained state of low-level contraction (such as in blood vessels) of smooth muscles. |
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Cardiac Muscle |
Primarily uninucleated, involuntary, striated. Connected by intercalated discs with many gap junctions connecting cytoplasm of adjacent cells. |
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Myofibrils |
Sarcomeres laid end to end, and surrounded by a covering called the sarcoplasmic reticulum (modified ER with high Ca+2 concentration). |
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Sarcoplasm |
Modified cytoplasm located just outside the sarcoplasmic reticulum. |
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Sarcolemma |
Cell membrane of a myocyte/muscle cell. Capable of propagating an action potential via transverse (T) tubules. |
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Myocyte |
Muscle cells. Contain many myofibrils arranged in parallel in a muscle fiber. Polynucleated. |
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Latent Period |
Time between reaching threshold and onset of contraction. During this time, action potential spreads along muscle and allows for calcium to be released from sarcoplasmic reticulum. |
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Frequency Summation |
When muscle fiber is exposed to frequent and prolonged stimulation with insufficient time to relax, contractions will combine, become stronger, and more prolonged. |
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Oxygen Debt |
Difference between amount of oxygen needed, and actual amount present. |