We hope you are enjoying the course! Last week's lectures can be challenging because we introduce many concepts that may be new to you. This module will allow you to apply some of the concepts that you learned last week and provide you with more concrete examples. In this module we will begin our tour of the various organ systems with the nervous system. We start by considering the function of the individual cells (neurons) and then how they interact as an integrative system. The nervous system provides rapid communication throughout the body coordinating the actions of trillions of cells. It responds to internal changes to the body as well as to changes in our external environment. This is a busy week. 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 Nervous System problem set. We suggest that you read the notes, watch the videos, and answer the in-video questions before you start on the problem sets. The problem sets require you to apply your knowledge from the lectures so it is best to be fairly familiar with the material before tackling them. The problem sets are not graded, and there is no due-date for them.