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Definition
| Skeletal and smooth muscle cells. Are elongated. |
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| The ability to recieve and respond to a stimulus. |
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| The ability to shorten forcibly when adequately stimulated. |
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| The ability to be stretched or extended. |
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Definition
| The ability of a muscle fiber to recoil and resume its resting length after being stretched. |
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Definition
| A fine sheath of connective tissue consisting of areolar and reticular fibers that surrounds each individual muscle fiber. |
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Definition
| Bundles of endomysium-wrapped muscle fibers. |
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Definition
| A layer of fibrous connective tissue that surrounds each fascicle. |
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Definition
| An overcoat of dense irregular connective tissue that surrounds the whole muscle. |
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Definition
| A red pigment that stores oxygen and is simular to hemoglobin. |
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Definition
| Each muscle contains many rodlike myofibrils that run parallel to its length. |
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Definition
| Type of myofilament. Extend the entire length of the A band. |
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Definition
| Type of myofilament. Extends across the I band and partway into the A band. |
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Definition
| Where the thick and thin filaments link toegther. Also known as the globular heads of a myosin molecule. |
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Definition
| A rod-shaped protein that spirals about the actin core and helps to stiffen it. |
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Definition
| A three-polypeptide complex. One of the polypeptides binds to actin, another binds to tropomyosin, and the third binds calcium ions. |
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Definition
| Region where a motor neuron comes into close contact with a skeletal muscle cell. |
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Definition
| The space that separates the axon terminal and the muscle fiber. It is filled with a gel-like extracellular substance rich in glycoproteins and collagen fibers. |
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Definition
| The troughlike part of the muscle fiber's ssarcolemma that helps form the neuromuscular junction. |
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Definition
| Loss of a state of polarity; loss or reduction of negative membrane potential. |
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Definition
| The restoration of polarity. |
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Definition
| During repolarization a muscle fiber is said to be in a refractory period because the cell cannot be stimulated again until repolarization is complete. |
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Definition
| Stage of the muscle twitch. The first few miliseconds following stimulation when excitation-contraction coupling is occuring. During this period muscle tension is beginning to increase but no response is seen on the myogram. |
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Term
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Definition
| Stage of the muscle twitch. The period when cross bridges are active and the myogram tracing rises to a peak. |
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Definition
| Stage of the muscle twitch. The period that is initiated by reentry of calcium into the SR. Muscle tension decreases to zero and the tracing returns to the baseline. |
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Definition
| At this point all evidence of muscle relaxation disappears and the contractions fuse into a smooth, sustained contraction plateau. |
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Term
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Definition
| The phenomenon where even relaxed muscles are always slightly contracted. |
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Definition
| A unique high-energy molecule stored in muscles. It is tapped to regenerate ATP while the metabolic pathways are adjusting to the suddenly higher demands for ATP. |
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Definition
| Occurs in the mitochondria. It requires oxygen and involves a sequence of chemical reactions in which the bonds of fuel molecules are broken and the energy released is used to make ATP. |
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Definition
| Energy-yielding conversion of glucose to lactic acid in various tissues, notably muscle, when sufficient oxygen is not available. |
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Definition
| A state of physiological inability to contract even though the muscle still may be recieving stimuli. |
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Definition
| States of continuous contraction because the cross bridges are unable to detatch. |
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