In this lesson, you'll continue learning about the organ systems. To start out, you'll see how human organ systems are interrelated and how a problem with one system will affect the others. You'll then move on to a discussion of the integumentary (skin), digestive, urinary, respiratory, and reproductive systems. You'll learn about each system's organs, function, and some common disorders. You'll finish the lesson with a discussion of the most important concept in human physiology—homeostasis. Homeostasis means the drive of your body to keep many different variables, like blood pressure and temperature, within a certain range. You'll find out why this is so crucial and how you might be asked to monitor homeostasis while caring for patients.