Answer
Tetanus is a state of sustained contraction of a muscle. It is normal part of skeletal muscle functioning. If a stimuls reaches or excedes threshold eery time a muscle is stimulated it will contract (twitch) and then respond between contractions (twitches). If a threshold stimulus of constant strength is administered to a muscle, with increasing frequency, the following pattern of responses will ensue:
1, The relaxation time between twitches will get shorter and shorter.
2. The concentration of Ca++ ions in the cytosol of the myocyte will get higher and higher.
3. The degree of wave summation will get greater and greater and the responses will progress to the point of a sustained shivering contraction. This is incomplete tetanus.
Work Step by Step
If the frequency of the stimulus continues to increase, a point is attained where the muscle responds with maximal tension. At that point evidence of twitch relaxation disappears, and the graph of the contractions fuse into a smooth sustained plateau. This is fused or complete tetanus.
