| A | B |
|---|
| actin | a protein in a muscle fiber that, together with myosin, is responsible for contraction and relaxation |
| antagonist | a muscle that acts in opposition to a prime mover |
| aponeurosis | a sheetlike tendon by which certain muscles are attached to other parts |
| fascia | a sheet of firous connevtive tissue that encloses a muscle |
| insertion | the end of a muscle that is attached to a movable part |
| motor neuron | a meuton that transmits impulses from the central nervous system to an effector |
| motor unit | a motor neuron and the muscle fibers associated with it |
| muscle impulse | like a nerve impulse, is generated, and the impule passes in all directions over the surface of the muscle fiber membrane |
| myofibril | one of the contractile fibers found within muscle cells |
| myosin | a protein that, together eith actin, is responsible for muscular contraction and relaxation |
| neurotransmitter | a chemical substance secreted by the terminal end of an axon that stimulates a muscle fiber contraction or an impulse in another neuron |
| origin | the end of a muscle that is attached to a relatively immovable part |
| oxygen debt | the amount of oxygen that must be supplied following physical exercise to convert the accumulated lactic acid to glucose |
| prime mover | a muscle that is mainly responsible for a particular body movement |
| recruitment | increase in the number of motor units activated as the intesity of stimlation increases |
| synergist | muscle that assists the action of a prime mover |
| threshold stimulus | the level of stimulation that must be exceeded to elicit a nerve impulse or a muscle contraction |
