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Muscles
muscles
| Term | Definition |
|---|---|
| Contractility | The ability of skeletal muscle to shorten with force |
| Excitability | The capacity of skeletal muscle to respond to a stimulus |
| Extensibility | The ability to be stretched |
| Elasticity | ability to recoil to their original resting length |
| Empimysium | Connective tissue sheath surrounding the skeletal muscles |
| Facia | is another connective tissue located outside the epimysium |
| Fibers | faciculi are composed of single muscle cells |
| Endomysium | each fiber is surrounded by loose connective tissue |
| Myofibrils | A thread like structure that extends from one end of the fiber to the other |
| Actin Myofilaments | Thin myofilaments |
| myosin myofilaments | thick myofilaments |
| sarcomeres | are joined end to end |
| resting membrane potential | charge difference across the membrane |
| action potential | brief reversal back to charge |
| motor neurons | a nerve cell that carry action |
| neuromuscular junction | each branch connects to muscle |
| synapse | near the center of the cell |
| motor unit | form a single muscle |
| presynaptic terminal | space between the presynaptic terminal |
| synaprtic vesicles | contains presynaptic terminal |
| acetylcholine | diffuses across synaptic cleft |
| acetylcholinesterase | rapidly broken down by enzymes |
| sliding filament mechanism | sliding of actin myofiliments |
| muscle twitch | contraction of an entire muscle |
| threshold | will not respond to stimulants |
| all or none response | phenomenon |
| lag phase | beginning of contraction |
| contraction phase | time of contraction |
| relaxation phase | time when muscle relaxes |
| tetany | muscle remains contracted |
| recruitment | increase in number of motor units |
| creatine phosphate | can store high energy molecules |
| anaerobic respiration | without oxygen |
| aerobic respiration | with oxygen |
| oxygen debt | amount of oxygen needed for chemical reaction |
| muscle fatigue | used during muscle contraction |
| isometric | length of muscle does not change |
| isotonic | amount of tension produced |