1. Human Anatomy & Physiology
Urinary System
Human Anatomy & Physiology

3. Urinary System Function
Kidneys
Eliminate chemical/metabolic waste
Nitrogenous wastes (byproducts of chemical reactions that are no longer useful such as ammonia, urea, uric acid, creatinine)
Control the volume and composition of body fluids
Water/salt balance
Blood volume is closely associated with the salt balance of the body
The more salt in the blood, the greater the volume of blood and the greater the blood pressure
The kidneys are involved in regulating blood pressure and also maintain appropriate levels of certain ions in the blood
Acid/base balance
The kidneys monitor and control blood pH through the excretion and reabsorption of certain ions
Main organ of excretion (make urine)
Principal job is the removal of urea and the regulation of water in the bloodstream
Convert Vitamin D to active form

4. Waste Products Urea Ammonia Creatinine
End product of amino acid metabolism in body cells
Water soluble
Primary end product of the urinary system
Ammonia
End product of the deamination of amino groups
Very toxic to tissues
Converted to urea in the liver in land mammals
Creatinine
End product from creatinine phosphate in muscle metabolism

5. Structures of the Urinary System
Kidney
Reddish brown organs
Size of a bar of soap
Located in the superior lumbar region; on either side of the spinal column, anchored against the dorsal body wall by connective tissue
Responsible for excretion of urine and regulation of blood volume and pH

6. Structures of the Urinary System
Renal Vein
Carries blood from the kidneys back to the heart

7. Structures of the Urinary System
Renal Artery
Carries blood into the kidney

8. Structures of the Urinary System
Ureter
Muscular tube
Moves urine from the kidneys to the bladder through peristalsis

9. Structures of the Urinary System
Urinary Bladder
Urine storage, can hold up to 600 to 1000 mL of urine
Expands and contracts
Stretch receptors indicate when it is full, signal notifies the brain resulting in the desire to urinate

10. Structures of the Urinary System
Urethra
Tube that connects the urinary bladder to the outside

11. Kidneys Composed of over 1 million nephrons Produces urine
Positioned so that urine flows into a collecting duct with several nephrons entering the same collecting duct

12. Kidney Anatomy Hilum Renal Cortex Renal pelvis Calyces Renal capsule
Adipose capsule
Renal Medulla
Medullary pyramids
Renal columns
Nephron

14. 3 main regions of the kidney
Renal Cortex
Renal Medulla
Renal Pelvis

15. Renal Cortex Superficial
(outer granulated layer)
Dips down in between a radially striated or lined inner layer
Light in color

16. Renal Medulla Deep to the renal cortex Darker in color
Consists of cone-shaped tissue masses called renal pyramids

17. Renal Pelvis
Central space or cavity that is continuous with the ureter
Collecting ducts empty into this region

18. Hilum Medial indentation
Point of entry for renal artery and renal nerves
Point of exit for renal vein and ureter

19. Calyces Form cup shaped area Enclose the tip of the medullary pyramids
Collect urine

20. Kidneys protected and stabilized by connective tissue:
Renal capsule
Encloses kidney
Gives glistening appearance
Adipose capsule
Fatty mass that helps hold kidney in place
Surrounds renal capsule

21. Medullary Pyramids
Triangular regions with a striped appearance

22. Renal Columns
Separate the medullary pyramids

23. Blood Supply
Kidneys receive 20–25% of total cardiac output

24. Blood Flow Renal artery Segmental artery Lobar artery
Interlobar artery
Arcuate artery
Interlobular artery
Interlobular vein
Arcuate vein
Interlobar vein
Renal vein