Muscle Physiology
Purpose:
The Purpose of this exercise is to understand how muscle twitch, contract and react to different activities.
Exercise 1: Muscle Twitch
A. What is a muscle twitch? A muscle twitch is the fasciculation , or "muscle twitch", is a small, local, involuntary muscle contraction and relaxation visible under the skin.
B. According to the graphs, which muscle has the fastest twitch? Why?
The lateral rectus eye muscle has the fastest twitch. It has the shortest latent period, or the shortest period of time between the stimulus and its response.
C. What is the latent period and why does it occur?
The latent period is the first stage of a muscle twitching. It is the time that elapses between the stimulus and its response.
Exercise 2: Treppe
A. Why is treppe an important phenomenon for athletes to understand?
The phenomenon in which the contraction strength of a muscle increases, due to increased calcium availability and enzyme efficiency during the warm-up. An athlete can perform better when he or she knows when her performance will peak. In this case the muscle will reach its maximum potential after a warm-up.
B. Physiologically, what causes treppe to occur? A treppe occurs when more forcefully after it has contracted a few times then when it first contracts. This is due to the fact that active muscles require decreasing degrees of succeeding stimuli to elicit maximal contractions
Exercise 3: Wave Summation A. Explain why wave summation occurs. Wave summation occurs when a second stimulus is applied before the first stimulus is lost. The two responses combine to produce a greater muscle tension than produced be a single response.
B. Can summation go on infinitely? Why or why not? If the stimulation continues and muscle never reaches its relaxation period, tension will rise to a peak. A muscle producing peak tension during rapid cycles of contraction and relaxation is