Biology Regents Practice Exam 2025 - Free Practice Questions and Study Guide

The excretory system, also known as the urinary system, is essential for regulating water balance in the body. This system is responsible for filtering waste products from the blood and excreting them through urine. Key components of the excretory system, such as the kidneys, play a vital role in maintaining homeostasis by adjusting the volume and concentration of urine based on the body's hydration levels. When the body is dehydrated, the kidneys conserve water by concentrating the urine, whereas when there is excess water, they dilute the urine and excrete more.

Understanding the role of the excretory system provides insight into how the body maintains its internal environment, ensuring that hydration and electrolyte balance are kept within optimal ranges for proper functioning. This regulation is crucial for preventing conditions such as dehydration or overhydration, which can disrupt physiological processes.