Learn more: http://www.khanacademy.org/video?v=Tbq-KZaXiL4
How one neuron can stimulate (or inhibit) another neuron at a chemical synapse

Length: 9 minutes

Myosin and Actin

Length: 9 minutes

Tropomyosin and troponin and their role in regulating muscle contraction

Length: 14 minutes

Role of the Sarcoplasmic Reticulum in Muscle Cells