I like videos that dumb things down...inspiration and expiration for dummies. I thought it was helpful to see the changes of barometric and aveolar pressure.
Neuronal Control Of Inspiration and Expiration:
This picture was actually taken from our Anatomy 211 textbook. Although it was difficult to understand at first, the further I read about the medullary and pontine respiratory centers, the easier it was to understand the diagram and also how the neurons fire inspiration and expiration.