A&P Frog Lab

The change in skin voltage

The detection and recording of AP

1) Gradual activation of more motor neurons

2) Increase frequency of motor neuron action potential for each active motor unit

a smooth, sustained muscle contraction that results from high frequency stimulation (frequency of AP delivered to the motor units)

A condition in which the muscle gradually loses some or all of its ability to contract after contracting for an extended period of time

procedure of measuring the force

visual recording of force

Interval from stimulus application until the muscle begins to shorten

The voltage at which the first perceptible contractile response is obtained

no matter how much more voltage is applied there are no more muscle fibers to contract (all muscle cells stimulated)

a phenomenon in which when a muscle is stimulated with a rapid series of stimuli of the same intensity before it has had a chance to relax completely, the response to the 2nd and subsequent stimuli is greater than the 1st stimulus

stimulation of a muscle at an even higher frequency, producing a “fusion” (complete tetanization) of the summated twitches, where there is absolute no relaxation observed

the phenomenon of gradual increase in the extent of muscular contraction following rapid repeated stimulation

Increasing the voltage used to stimulate the muscle will increase the number of motor units contracting at the same time

compound action potential, is the electrical signal recorded from a nerve representing the summed electrical activity of all the nerve fibers