Term
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Definition
| Skeletal, smooth, & cardiac |
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Definition
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Definition
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Definition
| Connect bone to other bone |
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Definition
| Reducing the angle of a joint |
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Definition
| Increasing the angle of the joint |
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Term
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Definition
| Moving away from the body's midline |
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Term
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Definition
| Moving toward the body's midline |
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Term
| Origin of skeletal muscle |
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Definition
| Muscular attachment to bone closer to the center of the body. |
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Term
| Insertion of skeletal muscle |
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Definition
| Muscular attachment to bone further from the center of the body. |
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Term
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Definition
| Muscles that are responsible for movement in opposite directions |
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Definition
| Muscles that are responsible for movement in the same direction |
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Term
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Definition
| Bundle of myofiber (muscle fiber) |
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Term
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Definition
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Definition
| Formed by the fusion of individual cells during development. Innervated by a single nerve ending. Stretch the length of the muscle. |
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Term
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Definition
| Cell membrane of myofiber. Composed of the plasma membrane and an additional layer of polysaccharide and collagen. Helps the cell to fuse with tendon fibers. |
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Term
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Definition
| Generates contractile force of skeletal muscle. Building blocks of myofiber. Is a specialized organelle. |
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Term
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Definition
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Definition
| Polymerized myosin (has ATPase activity) |
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Term
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Definition
| Contractile unit of muscle cells |
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Term
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Definition
| Boundary between sarcomeres |
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Term
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Definition
| Region of sarcomere composed only of thin filaments (actin) |
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Term
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Definition
| Full length of the thick filament (myosin) as well as the overlapping region of the thick and thin filaments |
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Term
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Definition
| Region of sarcomere composed only of thick filaments (myosin). Only present in resting sarcomeres. |
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Term
| Zones/Bands that contract as the sarcomere contracts |
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Definition
| I Bands and H Zones contract as the sarcomere contracts. The A Band length doesn't change. |
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Term
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Definition
1) Binding of myosin head to a myosin binding site on actin => forming a cross bridge. Myosin has ADP and inorganic phosphate bound.
2) Power Stroke: myosin head moves to a low-energy conformation, and pulls the actin chain toward the center of the sarcomere. ADP is released.
3) Binding of new ATP molecule is needed for release of actin by the myosin head.
4) ATP hydrolysis => myosin head changes to high-energy conformation. |
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Term
| Troponin-Tropomyosin Complex |
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Definition
| Tropomyosin winds around actin and covers all the myosin binding sites. When Troponin( which is bound to Tropomyosin) binds calcium, it changes conformation. This causes Tropomyosin to uncover myosin binding sites. |
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Term
| Neuromuscular Junction (NMJ) |
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Definition
| Synapse between an axon terminus and a myofiber. Long invagination of the cell membrane. This allows the neuron to depolarize a large region of the postsynaptic membrane at once. |
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Term
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Definition
| Postsynaptic membrane (myofiber cell membrane) |
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Term
| Neuromuscular Junction neurotransmitter |
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Definition
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Term
| End Plate Potential (EPP) |
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Definition
| Depolarization of myofiber cell due to Na influx via ACh binding |
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Term
| Transverse Tubules (T-Tubules) |
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Definition
| Deep invaginations of the cell membrane, which allow the AP to travel into the thick cell |
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Term
| Sarcoplasmic Reticulum (SR) |
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Definition
| Specialized SER which sequesters and releases Ca |
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Term
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Definition
| Smallest measurable muscle contraction |
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Term
| Means of increasing the force of contraction |
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Definition
1) Motor unit recruitment: Activation of multiple motor neurons.
2) Frequency summation: Multiple contractions with little delay in between. Can result in tetanus if continued. |
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Term
| Length-Tension Relationship |
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Definition
| A muscle contracts most forcefully at an optimum length (2.2 microns) |
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Term
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Definition
| Intermediate-term energy storage molecule used due to the fact that glycolysis and the TCA cycle are not fast enough to keep up with the rapid ATP usage. |
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Term
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Definition
| Globular protein that provides an oxygen reserve by taking oxygen from Hb and releases it as needed. |
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Term
| Type I Slow Twitch Fibers |
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Definition
| Red oxidative fibers. Lots of mitochondria. Slow speed of contraction. Low force generated. High fatigue resistance (~hours). |
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Term
| Type IIA Fast Twitch Fibers |
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Definition
| Intermediate, fast twitch oxidative. Intermediate speed of contraction. Medium force generated. Some mitochondria. Medium density of capillaries. Medium fatigue resistance (~30 minutes). |
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Term
| Type IIB Fast Twitch Fibers |
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Definition
| White fast twitch. Very fast speed of contraction. High force generated. Very few mitochondria. Very few capillaries. Low fatigue resistance (~1 minute). |
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