A skeletal muscle.
Skeletal muscle
The tricep is the muscle on the underside of the upper arm. The muscle on the upper side is the bicep.
The tricep muscle is mainly responsible for the straightening of the arm. This means that the tricep muscles are voluntary, and will only move if we wish to move our arms.
tricep
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.
There are two main ones, the tricep and the biscep. The tricep bicep is on the inside angle as defined by your elbow, the tricep is on the outside.
your tricep
Tricep.
Tricep
tricep and bicep
Tricep.
tricep!
Tricep