1. The Urinary System Chapter 26

2. Functions Regulating blood volume and blood pressure Regulating blood volume and blood pressure Regulated concentration of sodium, potassium, chloride, etc. Regulated concentration of sodium, potassium, chloride, etc. Stabilizes blood pH Stabilizes blood pH Conserves nutrients and gets rid of waste Conserves nutrients and gets rid of waste Assists liver in detoxifying poisons Assists liver in detoxifying poisons

3. Organization Excretion- removal of waste from body fluids Excretion- removal of waste from body fluids Elimination- discharge of these wastes from the body Elimination- discharge of these wastes from the body Kidneys Kidneys Ureters Ureters Urinary bladder Urinary bladder Urethra Urethra

5. Kidneys Hilus- medial indentation, location of entry and exit of renal artery and vein Hilus- medial indentation, location of entry and exit of renal artery and vein Nephron- microscopic tubular structures, begins process of urine production, 1.25 million in each kidney Nephron- microscopic tubular structures, begins process of urine production, 1.25 million in each kidney

7. Nephron Renal Corpuscle- region called Bowman’s capsule, which is a network of capillaries Renal Corpuscle- region called Bowman’s capsule, which is a network of capillaries Blood pressure forces fluid and dissolved solutes out of the capillaries Blood pressure forces fluid and dissolved solutes out of the capillaries The filtrate enters the renal tubule The filtrate enters the renal tubule Reabsorption of useful organics, 90% of the water Reabsorption of useful organics, 90% of the water Secretion of any waste products Secretion of any waste products

9. Renal Physiolgy Urea- most abundant organic waste, created by the breakdown of amino acids Urea- most abundant organic waste, created by the breakdown of amino acids Creatinine- generated by the breakdown of creatine phosphate, used in muscle contraction Creatinine- generated by the breakdown of creatine phosphate, used in muscle contraction Uric acid- formed from nitrogenous bases of RNA Uric acid- formed from nitrogenous bases of RNA Water must be used to get rid of these waste products Water must be used to get rid of these waste products

10. Control of Urine Volume Regulated by reabsoption of water Regulated by reabsoption of water ADH (anti-diuretic hormone)- highter circulating levels increase amount of reabsorption of water ADH (anti-diuretic hormone)- highter circulating levels increase amount of reabsorption of water

11. Composition of normal urine pH = 6 pH = 6 Water = 93-97% Water = 93-97% Color = clear yellow Color = clear yellow