In this lesson, we start to look at how brains make things happen, in other words how our brains control our muscles so that we can take an active part in the world. 

We will "start at the bottom and work our way up", looking at how muscles are structured, how they produce contractions and how these contractions are controlled by action potentials in muscle fibers which are triggered by inputs from motorneurons that live in the spinal cord. 

We will briefly look at reflex circuitry and "central pattern generators" in the spinal cord can control simple (or not so simple) movement patterns before moving on to a discussion of how movement intentions are thought to be encoded by activity of populations of neurons in motor cortex.