Welcome to module 11 and the last organ system to be covered in this course! In this module, we turn our attention to the urinary system and specifically to the functions of the kidney, a filter of the blood. The kidney is a complicated organ whose actions integrate with those of the cardiovascular system to maintain blood pressure and with the respiratory system to maintain acid-base balance. As we progress through this module, we consider the mechanisms by which the kidney regulates the water content and the electrolyte content of the body. We focus on the roles of the normal kidney but also consider changes in homeostasis due to either disease or drugs. The last lesson of this module considers the role of the kidney in regulating acid-base balance of the body and its integration with the respiratory system. The things to do this week are to watch the 6 videos, to answer the in-video questions, to read the notes, and to complete one problem set (urinary system). In this module, the sequence of videos is important. As you proceed through the videos and notes, try to correlate the specific region of the renal tubule with its function. Often this is best achieved by drawing the renal tubule and labeling the specific changes in structure and function. Again, the notes will provide a more detailed summary of the material presented in the videos. Please note that the first two videos correlate with the first set of notes and the third video with the second set of notes. We encourage you to complete the problem set. The problem set is not graded and is for your personal feedback. Both your understanding and retention will increase with application of the new learned information.