lab 7

coactivation

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muscle basal activity

Electrical activity recorded in a muscle while it is at rest or when it is not being contracted.

electromyogram

a graphical record of electric currents associated with muscle contractions

action potential

a neural impulse; a brief electrical charge that travels down an axon

ex2

elbow at 90 degrees flex and extensorhave peroson press their fingers on underside of table to extend (have them face away)have person flex for 5 sec then rest 5 secos and flex again to practice. then record and have the person flex and rest until there is a relationhsip bewtween the two on recording. stop.

explain how muscles could be opposing and still be activie at the same time

isometric contractions generate tension but no shortening

ex3

leg emg of t a and gast. have person stand on toes and res while recording. have person sit, stand on both feet, stand with feet elevated at heel with one book, two book then three books. then stand with book and toes elevated, stand on tiptoe with book -and stand on tip toe with one foot wihle other is elevated-leaning foward, standing, leaning backward

isotonic contraction

muscular contraction in which the muscle remains under relatively constant tension while the length changes (origin and insertion approximate)

motor end plate

specialized area of sarcolemma of the muscle fiber which contains receptor sites for neurotransmitters

ex 1

tests using arm flexors and extensors to testing contractions via making fists and resting hand against table (relaxing and not relaxing )time increased-flex fingers individually and flex 3 seconds, record time varried and was -BOOKS contraction incraesed as more books were used emg went up,

isomentric contraction

the tension generated is not enough to exceed the resistance of the object to be moved and the muscle does not change its length.