Practice and Revision - The Excretory System
Let us practise and revise what we learned about the excretory system. The excretory system removes metabolic wastes from the body, with the
Core concept
Nephrons, the functional units of kidneys, filter blood through a process involving filtration, reabsorption, and secretion to form urine.
How it works
Filtration occurs in the glomerulus, where blood pressure forces water and small molecules into the Bowman's capsule, forming a filtrate.
Why it matters
Reabsorption occurs along the tubules, where useful substances like glucose and water are returned to the blood, concentrating the urine.
Key detail
The kidneys also help regulate blood pressure, pH balance, and water balance in the body, essential for maintaining homeostasis.
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Quick notes
• Nephrons: functional units of kidneys.
• They filter blood forming urine.
• Steps: filtration, reabsorption, secretion.
• Filtration occurs in the glomerulus.
• It forms a filtrate in Bowman's capsule.
• Reabsorption occurs along tubules.
• Useful substances (glucose, water) return to blood.
• Kidneys regulate blood pressure, pH, water balance.