Structural integration’s focus is not primarily on the muscles but on the fascial network. Fascia is a specialized system of the body that has an appearance similar to a spider's web. It is very densely woven, covering and interpenetrating every muscle, bone, nerve, artery and vein, as well as, all of our internal organs including the heart, lungs, brain and spinal cord. The most interesting aspect of the fascial system is that it is actually one continuous structure that exists from head to toe without interruption. Each part of the entire body is connected to every other part by the fascia, like the single strand of yarn that makes up a sweater: pull on one thread and the whole garment is affected!