Summary The function of the kidney in homeostasis

This document explains how the kidneys help maintain a stable internal environment in the body by controlling water balance, filtering waste, and regulating salt levels. It describes the structure and function of the excretory system, showing how blood enters the kidneys through the renal artery, is filtered in structures called nephrons, and how waste leaves as urine through the ureters and urethra. The document also covers how kidney function can be assessed by checking for glucose or red blood cells in urine, which can indicate diabetes or kidney damage. It compares treatments for kidney failure - dialysis and transplants - highlighting their advantages and disadvantages. Additionally, it explains how dialysis mimics kidney function using a selectively permeable membrane to remove urea from the blood. The document includes diagrams of the nephron and details how the hormone ADH controls water reabsorption, showing how the brain regulates urine concentration through negative feedback. Overall, it provides a clear overview of how the kidneys maintain homeostasis and what happens when they fail.