Please answer these in a phrase or sentence. In this figure describing muscle co
ID: 66565 • Letter: P
Question
Please answer these in a phrase or sentence. In this figure describing muscle contraction, the Y axis represents tension and X axis is time. The arrows at the bottom indicate action potentials from the motor neuron. The questions refer to that figure. The action potentials are all the same voltage. What is happening inside the muscle fiber to make the second AP to create more tension than the first? Do you think that this is an isotonic or an isometric movement? Justify your answer. At what point is tetanus reached on this graph?Explanation / Answer
(a). Wave summation is an increasingly stronger contraction owing to stimulation at a rapid rate. Rapid stimulation of a muscle fibres (applied during contraction period) causes summation of the contractions , which indicates a stronger contraction of the muscle. The graph is representing wave summation.
(b). The grapg is representing isotonic contractions (because muscle length is not constant). During isotonic type of contraction, the length of the fibre changes but the muscle tension remains constant (Eg: simple flexion of arm involves isotonic contraction). In the laboratory experiments with frog muscle, we can observe the isotonic contraction, where the length of the muscle fibre changes. Thus, isotonic contractions are the most common type of contractions that occur during laboratory experiments.