Unit 3- Lab Project- Build a Limb

For this lab project I had to build a human limb, bones that meet at a joint, a muscle pulling on that bone, muscle cell showing how actin-myosin filaments make it contract and neurons that go to muscle cells triggering contraction. For the limb I chose a human leg. The supplies for my project included clay to show the muscle, skeleton bones left over from halloween, pipe cleaners for the neurons and actin-myosin, crazy eyes to show sodium ions and potassium ions, construction paper for labeling, pieces of a straw to show schwann cells and grape stems.

This is a picture of the supplies I used:
This is my human limb, the leg. The red clay on it is showing the muscle.

This is the leg laying down so that I could label the parts:

This is my version of an axon with the schwann cells. The little red pieces are the straw and the grape stem is the axon terminal and the dendrites.

Here I am showing the propagation of action potential along the axon:

This is the muscle cell, the sarcomeres are relaxed here, they are shorten:

And here the sarcomeres are contracted:

This picture is of the sodium ions (Na+) gates opening and starting to move inside the axon. Na+ goes before K+.

This is what happens next, the Na+ gates close allowing potassium ions (K+) to move out of the axon.

So in conclusion my models show the human limb and the muscle on it, the action potential and actin-myosin filaments that are required to get a limb to move and the axon with the schwann cells. This project has helped me to understand how our limbs move and what makes muscles contract. Without action potentials and actin-myosin filaments how would are limbs move?