Muscle fiber generates tension through the action of actin and myosin cross-bridge cycling. While under tension, the muscle may lengthen, shorten or remain the same. Although the term 'contraction' implies shortening, when referring to the muscular system, it means muscle fibers generating tension with the help of motor neurons
when a muscle contracts,it becomes
longer
relaxes
The bicep muscle. The tricep contracts to straighten the arm as the bicep relaxes.
Relaxes
contract
gdg
the smooth muscle
I think what your after is called an antagonistic pair of muscles, for example the bicep and the tricep. When the bicep is contracting the tricep relaxes and when the tricep is contracting the bicep relaxes.
It Contracts
antagonist.
It relaxes
A muscle that contracts shortens whereas a muscle that relaxes lengthens.
false