The Excretory System: Organs, Functions, and Vital Role in Health

The excretory system removes metabolic waste products that would otherwise accumulate to toxic levels. It maintains fluid, electrolyte, and acid-base balance.

Key Organs and Functions

• Kidneys: Filter blood, remove wastes (urea, creatinine, excess ions), regulate water/electrolyte balance, produce urine.
• Ureters: Transport urine from kidneys to bladder via peristalsis.
• Bladder: Stores urine (capacity ~400–600 mL) until voluntary voiding.
• Urethra: Expels urine from the body.

Process Overview

1. Blood enters kidneys → filtered at glomeruli → filtrate enters tubules.
2. Essential substances (glucose, amino acids, water, electrolytes) are reabsorbed.
3. Wastes and excess substances remain in tubule → become urine.
4. Urine travels ureters → stored in bladder → expelled via urethra.

The excretory system is essential for homeostasis and overall health. Kidney dysfunction can lead to life-threatening imbalances.