posted by Sara .
Situation: You need to step up on a step to reach an object on a high shelf.
Instructions: (Part one) Trace the nerve 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. Include the steps involved in transmitting the impulse from one neuron to another and then to the muscle fiber. Include in this the steps involved in the actual muscle fiber contraction – Sliding filament theory. (Part two) Specify which muscles are pulling on which bones and what types of joints are involved in stepping up on the step. Next, specify which muscles are pulling on which bones and what types of joints are involved to reach up above your head to the shelf.