So the biceps triceps system works together in an autogenous manner. So the triceps biceps system is controlled antagonistically. And what that basically means is when one of these muscles contracts, the other muscle actually stretches, it elongates and vice versa. So let's take a look at diagram A and diagram B. So let's suppose I have my arm oriented as shown and I wish to pull it, so I wish to flex my arm and pull it towards my body. So basically what's happening is the central nervous system is creating an electrical signal.