In: Anatomy and Physiology
14. A sarcomere is very stretched, will it create a lot of force?
15. A sarcomere has optimal overlap, how much force (maximum, middle, minimum) would it generate? 16. Would a smooth muscle function properly if there was not enough Ca++ in the ECF? Explain.
14. If the sarcomere is very stretched, there will be insufficient overlap of the myofilaments and the less force will be produced.
15. Maximal active force is generated at lengths close to the resting length or the optimal overlap of the muscle. due to length tension relationship.
16. Ca++ is the main source of smooth muscle contraction. In case of nervous, the depolarization occurs with sodium entry and hyperpolarisation occurs with potassium entry. Like that for smooth muscle contraction calcium entry was important.
According to its mechanism, if there is only enough calcium in the ECF, calcium influx occurs then the muscle becomes depolarized thus the muscle contraction occurs. So if there is no enough calcium in ECF, it will affect the smooth muscle contraction.
But it will not completely shutdown because as a self repairing mechanism. The smooth muscle have sarcoplasmic reticulum, it is a rich source of calcium. So if there is not enough calcium in ECF. The acetylcholine from the synaptic cleft enters into the cell and stimulates the sarcoplasmic reticulum and stimulates the calcium influx and promotes smooth muscle contraction.