10.1 What is Excretion?
- Definition: The process of removing waste products from the body.
- Waste Products: Urea, Carbon Dioxide, Excess Water.
10.2 The Human Excretory System
| Part | Function |
|---|
| Kidneys | Filter blood, remove urea, water, salts. |
| Ureters | Transport urine from kidneys to bladder. |
| Bladder | Stores urine. |
| Urethra | Expels urine from the body. |
10.3 The Nephron
- Functional Unit of the kidney.
- Functions: Filtration, reabsorption, secretion.
10.4 Ultrafiltration
- Blood is filtered at high pressure in the glomerulus into Bowman’s capsule, removing small molecules (e.g., urea).
10.5 Reabsorption
- Glucose, water, and ions are reabsorbed from the filtrate in the proximal convoluted tubule.
10.6 Secretion
- Waste products like excess ions and drugs are secreted into the nephron for excretion.
10.7 Osmoregulation
- ADH (Antidiuretic Hormone) controls water reabsorption to regulate water balance.