Let’s begin by talking about the extremities, the structures responsible for interacting with the environment, locomotion, weight bearing, and many more. The upper limb consists of four main parts: shoulder, arm, forearm, and hand. In turn, the mobility of the limb is provided by the shoulder, elbow, and wrist jointsonto which various muscles act. However, their action depends on innervation, and their viability on proper nutrition and blood supply. Do you know the name of the vein punctured by the needle when you have your blood drawn? How about the name of the nerve that can lead to tingles if you lean on your elbows for a long time?