The total number of muscles in the human body is:

Describe the important steps in muscle contraction.

In the given diagram,which label represents the $I$-band?

The strongest muscle of the body is found in

$A : Ca^{2+}$ plays an important role in muscle contraction.
$R : Ca^{2+}$ combines with the troponin chain,displacing tropomyosin and allowing the myosin head to combine with actin to form an actomyosin complex.

Where is troponin found during muscle contraction?