limb model lab write-up

intro


for this model me and a friend worked together to make a model of a movable arm with neuron triggering muscle to pull on bone and make joint move.I drew a basic diagram of how small the sarcomere is and also where in the limbs they are located as well as how they cause muscles to relax and contract.





myosin cross bridges bringing actin filaments together and shortening muscle

demonstrated in next 2 pics/steps

release of calcium from sarcoplasmic reticulum :

calcium binding to myosin :

making a limb :

• use eye bolts to make hinge.
• wrap pipe cleaner around wire to create actin & myosin
• run string through actin so when pulled will slide by myosin
• attach other ends of strings to the insertions on the "bones"
• pull string to cause action.

here's a vid of the results





this is a picture of the "limb" relaxed a better view
contracted limb
arm joint
motor neuron with dendrites, schwann cells, axons, and axon terminals. Axon terminals attach to muscle cells and release ACh.

axon with shwann cells : the long part of the neuron that transmits nerve impulses from the cell body to the mylin sheath made by shwann cells

movement of action potential along axon is made quicker by jumping mylin sheath surrounding shwann cells

sarcolemma and T-tubule membrane tubes going into muscle to carry action potential throughout large cell



movement of charged sodium and potassium ions across membrane for next 3 pics



triggers switching sodium and potassium from previous 3 pics


conclusion

so basically my model shows that actin-myosin sarcomeres move to make the arm move.