Situation: You need to step up on a step to reach an object on a high shelf.

Instructions: (Part one) Trace the impulse, listing the steps in as much detail as possible, from which your brain sends the message to the appropriate muscles to step up one step. Specifically include the steps involved in transmitting the impulse from the neuron to the muscle fiber at the neuromuscular junction. Specify which muscles are pulling on which bones and what type of joints are involved. 
(Part two) Trace the impulse, listing the steps in as much detail as possible, from which your brain sends the message to the appropriate muscles to reach up above your head to the shelf. Include in this the steps involved in the actual muscle fiber contraction – sliding filament mechanism. Again, specify which muscles are pulling on which bones and what type of joints are involved.