In this module, we consider two types of cells: one that relays information to the central nervous system (brain) for interpretation and a second set, motor neurons which relay information away from the central nervous system to govern voluntary movement. The input pathway to the brain is mediated by specific cells called senses. The senses convert energy (such as light or heat) into an energy form (electrical potentials) recognized by neurons in the brain. The brain, in turn, interprets this information (as vision or pain) and then sends out a motor response via the motor neurons of the somatic nervous system to effector cells in the body. The motor neurons activate skeletal muscle to control breathing and the movement of the limbs. The things to do this week are to watch the 5 videos, to answer the in-video questions, to read the notes, and to complete the problem set. It will be most effective if you follow the sequence of videos. The notes provide a more detailed summary of each topic. We encourage you to find which resource (videos and/or notes) works best for you and to try the problems sets. The problem sets are not graded. Both your understanding and retention will increase with application of the new learned information.