The arm has a wide range of movements, including the swinging motion they experience when walking, running or jumping as well as the ability to be folded across the chest or raised above the head. The majority of muscles in the upper arm originate from the shoulder. Two of the main muscles in the upper arm are the biceps (front of arm) and triceps (back of arm), which run from the shoulder to the elbow. Their main role is to give the forearm power to thrust and bend. As they are the reasons it is possible to straighten your arm and also rotate your wrist and hand.
The main role of the bicep is to aid the arm during movements which involve it straightening.
Exercises:
Pull Downs
Dips
Close Grip Bench Press
Close Hands Press Up
Arm Extensions (seated and standing)
Arm Extensions (lying)
Bench Dip
Standing Arm Extension