So we see that the muscle actually consists of many divisions so inside the muscle we contain these fascicles. These fascicles actually contain our muscle cells and these muscle cells contain the myofibrils that are composed of these sarcommer subunits these sarcomere building blocks. Now since our muscle cell is actually so long it contains many nuclei and that means that our skeletal muscles are multinucleated. Now we know that just like our neurons muscle cells skeletal muscle cells do not actually divide by mitosis and the way that our skeletal muscle grows when we for example exercise is by increasing the thickness of our muscle cells so the muscle cell will actually increase in thickness. It will increase its diameter for example because we're going to grow our myofibos because the sacramentors will grow and this will increase the size of our muscle cells and will ultimately increase the size of the muscle overall. So that's what happens when we exercise in this concept this type of growing of the skeletal muscle is known as hypertrophy.