| A | B |
|---|
| Why heavy breathing accompanies prolonged exercise | oxygen debt |
| buildup of lactic acid that weakens a muscle contraction | fatigue |
| source of body heat | energy of contraction |
| a neuron and all the muscle fibers it stimulates | motor unit |
| the weakest stimulus from a neuron that can still initiate a contraction | threshold stimulus |
| Muscle fibers, when stimulated, will contract to their fullest or not at all | All-or-none principle |
| Rapid, jerky response to a single stimulus | twitch |
| graph of a twitch | myogram |
| apparatus on which a twitch is graphed | kymograph |
| period between application of the stimulus and the contraction | latent period |
| period when am uscle fiber cannot contract again even if stimulated | refractory period |
| sustained contraction that lacks even partial relaxation between stimuli | tetanus |
| when skeletal muscle contracts more forecefully to the same strength stimulus after it has contracted several times | treppe |
| contraction in which muscle shortens and produces movement | isotonic |
| contraction in which there is minimal shortening of the muscle but blood pressure increases | isometric |
| muscles increasein size due to | 1) increase in actin & myosin 2) increase in muscle fiber diameter 3) action of hGH and testosterone |
| sustained partial contractions of portions of skeletal muscle; due to alternating application of motor units | tone |
| describes muscle with little tone | flaccid |
| wasting away of muscle | atrophy |
| increase in muscle size | hypertrophy |
| attachment of a muscle to the stationary bone | origin |
| attachment of muscle to the movable bone | insertion |
| fleshy portion of muscle | belly |
| act as levers in body movement | bones |
| act as fulcrums in body movement | joints |
| act as resistance force in body movement | weight of body part |
| act as effort force in body movement | muscle contraction |
| the muscle that causes a desired action | agonist/prime mover |
| muscle that opposes the prime mover | antagonist |
| muscle that helps the prime mover function more efficiently | synergists |
