Page 3 - CH-8-8.5 MUSCLES

 We cannot control the movement of the cardiac muscles, that is, they

are involuntary in nature.
 Cardiac muscles are structured like the voluntary muscles.

 Working of muscles

 The contraction and relaxation of the muscles attached to the bones
help in the movement of the bones.
 When muscle contracts, it shortens and pulls the bone due to which the

bone move at that joint. A muscle can only pull a bone it cannot push a
bone. The muscles joined to our bones work in pairs. When one muscle