This chapter discussed the renal system, which is responsible for fluid balance, blood pressure regulation, fluid and electrolyte balance, and red blood cell production. It is also responsible for removing metabolic waste products and excess water from the body. The text explained that the nephron is the functional unit of the kidney, and each section of the nephron is responsible for some part of filtration, reabsorption, or secretion. Common conditions affecting these systems were identified. Fluid volume excess, a common manifestation of altered renal system function, was explained as being caused by systemic conditions such as hypertension and heart failure.