People have arms so they can reach things. For example, some people like to reach for the cookie jar, others like to use their arms to attach their hands to. and to wipe ur bum and also masturbation...
Technically 1 asthe arm is only the region of the upper limb that is between the sholder and elbow joint. That 1 is called the humerus. In the whole of the upper exretmist there are 30, humerus,...
The arm is made up of two main muscles (biceps & triceps) for the arm to move one of these muscles must contract and the other must relax. Which muscle does which depends on which way you are...