1. THE EXCRETORY SYSTEM
Controlling the Internal
Environment

2. Gross Anatomy of System
• Pair of kidneys
– Retroperitoneal
• Pair of ureters
• Urinary bladder
• Urethra

3. Gross Anatomy

4. Location of Kidneys
Retroperitoneal

5. Retroperitoneal Location

6. The Kidney
Pyramid Papilla
Cortex
Medulla
Hilum Column
Calyx
Pelvis
Ureter

7. Functions of Excretory System
• Regulate body fluids
– Volume, pH, composition
• Remove metabolic wastes from blood
• Control rate of RBC formation
• Regulate blood pressure
• Regulate absorption of calcium

8. Nephron
PCT
Bowman’s DCT
capsule
Vasa recti
Glomerulus
Ascending
Descending tubule
Tubule
Collecting duct

9. The Blood Supply to the
Kidney

10. Renal Corpuscle

11. Renal Corpuscle

12. Podocyte and the Filtration Process

13. Renal Corpuscle

14. Function of Renal Corpuscle
• Bowman’s capsule
• Glomerulus
– Filtration of blood
• Water
• Electrolytes
• Glucose
• Urea

15. Filtration Slits

16. Nephron

17. Tubules
Proximal Tubule
Distal Tubule

18. Function of Tubules
• Reabsorption of glucose
– Proximal convoluted tubule
• Reabsorption of water
– PCT, descending tubule, collecting duct
• Reabsorption of salts
– PCT, ascending tubule, distal con. tub.
• Reabsorption of urea
– PCT, collecting duct

19. Collecting Ducts
Cuboidal Epithelium lining ducts

20. Nepron with Vasa Recta

21. Function of Tubules
• Reabsorption of glucose
– Proximal convoluted tubule
• Reabsorption of water
– PCT, descending tubule, collecting duct
• Reabsorption of salts
– PCT, ascending tubule, distal con. tub.
• Reabsorption of urea
– PCT, collecting duct