Imagine a giant building is going to be built. Specific people are necessary to make it happen.
First, there's the Idea Guy – the one who comes up with the idea and loosely how to do it.
Then there's The Architect. This is the person who will design the building and create the blueprint for how to make it happen.
Lastly, there's The Foreman. This is the person that oversees the building being built to make sure it goes as planned.
Clearly creating a motor program in your brain is complicated, and not even fully understood by science, but the above analogy can help us make some sense of it.
The Idea Guy is the motor cortex found in the pre-central gyrus of the brain. This is roughly where the idea for the movement comes from as well as a general idea of how it should be done. For example, let's say you want to pick up a glass of water and drink it. The motor cortex makes some big decisions about it, like to use your hand instead of your foot, and then passes the idea along to The Architect, the basal ganglia.
The basal ganglia is where the movement is designed and a blueprint of sorts is created. For example, the basal ganglia determines when to start and stop the movement, and which muscles should be activated, versus which should be inhibited.
The blueprint then goes back up to The Idea Guy, the motor cortex, who can now execute the motor program.
However, we're not done yet.
To make sure the movement goes as planned and you don't miss the glass, or pour it over your forehead, The Foreman, the cerebellum, was also handed a copy of the blueprint and compares it to what is actually happening, and makes corrections as needed.
Learn this and more in the new course, Functional Physiology.