Calcium ion concentration in blood affects muscle contraction. Does it lead to tetany in certain cases? How will you correlate fluctuation in blood calcium with tetany?
Ans:
Muscle contraction is initiated by a neural signal from the central nervous system through a motor neuron. This occurs due to gradient of calcium ions. When calcium ions start entering the muscle cells, actin, and myosin filaments slide towards each other, resulting in contraction of muscle. When calcium ions come out of the muscle cells, actin and myosin filaments move back to their positions and the muscle relaxes.
Thus, a higher level of calcium ions in blood implies a lower level of calcium in muscles. This leads to poor contractility of muscles. Whereas, when the level of calcium in blood is low, higher level of calcium in muscles. This may result in an uncontrolled contraction of muscles called tetany.