Muscle Twitch Essay

In this experiment, we investigated electrically stimulated nerves n the forearm to display recruitment, summation, tetanus and conduction velocity of action potentials. Muscle are either directly joined to the bone or connected by tendons, which by definition are resilient bundles of collagen fibers. Motor nerves innervate the fibers of the skeletal muscles, which is controlled voluntarily. The action potential in a muscle fiber allows for an increase in the influx of calcium causing what we know as a twitch. A twitch is a contraction of the muscle due to only one action potential generated. Muscle nerves govern movements in a variation of ways. First is by recruitment, which simply means modifying the number of firing motor axons. Due to this definition, …show more content…
Experiments where devised using the computer program chart. In exercise 1, the bar stimulus electrode was placed over the volunteer’s ulnar nerve at the wrist to locate a spot where we could see the twitch contractions affecting the thumb and fingers. In exercise 2, we measured the muscular twitch response to nerve stimulation and showed recruitment in the twitch response as the stimulus strength increased by identifying the minimum amplitude (when the first response was graphed) and also the maximum (when the response no longer showed a change). Exercise 3, we changed the interval between paired stimulus pulses on muscle twitch force and observed a short tetanic contraction by setting the pulse current to 15 mA and beginning frequency at 2 Hz and moved up to intervals of 5, 10 and 20 Hz while also changing the number of pulses form 2 to 3, 3 to 4, and 4 to 5. Exercise 4 we recorded the EMG responses evoked by stimulating the median nerve at the wrist by similar steps done in exercise 2, identifying the minimum and maximum amplitudes responses. The data for exercise 2 that was recorded found a minimum of 7 mA and a maximum of