responds to the demands on a muscle by stimulating more limi

responds to the demands on a muscle by stimulating more limited units within that help it contract as load increases; this is to all of the number called motor unit recruitment. There are a limited number of motor units in a single muscle, so when motor units are recruited, maximum stimulation has reached been No matter how much willpower you have, if all the motor units are recruited and the force generated is not moving the load, then you are out of luck. Before you begin, familial concepts (use your prize yourself the following textbook a with Motor reference) unit. Neuromuscular junction R Skeletal muscle twitch and its parts (latent period, contraction period, period) relaxation Difference between subthreshold, threshold, and maximal stimulus. Isometric contraction and isotonic contraction State your hypothesis regarding how the isometric muscle twitch force of contraction is influenced by the changes in stimulus voltage.

Solution

At the subminimal voltage stimulus, the muscle does not contract as the current supplied does not have enough strength to excite muscle fibres for the muscle contraction. A threshold stimuls excites few motor units and give a weak contraction. A minimal stimuli contraction is recorded only with the break stimulus, because the break stimulus is stronger than the make stimulus As voltage current increases more and more units are recruited that result in increased magnitude of contraction. When the strength of stimulus reaches maximum level there is no increase in magnitude of contraction with further increase in strength of stimuli as the maximum number of motor units have been utilised already.