Question

Can anyone explain to me this process?
File attached:

Answer 1

Basically just an explanation of what the + and - mean.

Answer 2

maybe some chemical signal or electrical impulses from the brain......

Answer 3

Ok I think I got it, let me know if anyone else thinks this is right:
Inspiratory neurones => AP to inspiratory muscles, followed by AP to Expiratory neurones
Exiratory neurones => AP to expiratory muscles and SOMETHING to inspiratory neurones.

What is the Something?

Answer 4

Ok figured the rest out. Negative means negative signal to stop propagation.

Thanks anyway!

Answer 5

http://www.people.vcu.edu/~mikuleck/courses/resp2/sld001.htm
http://en.wikipedia.org/wiki/Control_of_respiration