The Urinary SystemThe Urinary System

Chapter 26Chapter 26

FunctionsFunctions

Regulating blood volume and blood pressureRegulating blood volume and blood pressure Regulated concentration of sodium, potassium, Regulated concentration of sodium, potassium,

chloride, etc.chloride, etc. Stabilizes blood pHStabilizes blood pH Conserves nutrients and gets rid of wasteConserves nutrients and gets rid of waste Assists liver in detoxifying poisonsAssists liver in detoxifying poisons

OrganizationOrganization

Excretion- removal of waste from body fluidsExcretion- removal of waste from body fluids Elimination- discharge of these wastes from Elimination- discharge of these wastes from

the bodythe body KidneysKidneys UretersUreters Urinary bladderUrinary bladder UrethraUrethra

KidneysKidneys

Hilus- medial indentation, location of entry Hilus- medial indentation, location of entry and exit of renal artery and veinand exit of renal artery and vein

Nephron- microscopic tubular structures, Nephron- microscopic tubular structures, begins process of urine production, 1.25 begins process of urine production, 1.25 million in each kidneymillion in each kidney

NephronNephron

Renal Corpuscle- region called Bowman’s Renal Corpuscle- region called Bowman’s capsule, which is a network of capillariescapsule, which is a network of capillaries Blood pressure forces fluid and dissolved solutes Blood pressure forces fluid and dissolved solutes

out of the capillariesout of the capillaries The filtrate enters the The filtrate enters the renal tubulerenal tubule

Reabsorption of useful organics, 90% of the waterReabsorption of useful organics, 90% of the water Secretion of any waste productsSecretion of any waste products

Renal PhysiolgyRenal Physiolgy

Urea- most abundant organic waste, created by Urea- most abundant organic waste, created by the breakdown of amino acidsthe breakdown of amino acids

Creatinine- generated by the breakdown of Creatinine- generated by the breakdown of creatine phosphate, used in muscle contractioncreatine phosphate, used in muscle contraction

Uric acid- formed from nitrogenous bases of Uric acid- formed from nitrogenous bases of RNARNA

Water must be used to get rid of these waste Water must be used to get rid of these waste productsproducts

Control of Urine VolumeControl of Urine Volume

Regulated by reabsoption of waterRegulated by reabsoption of water ADH (anti-diuretic hormone)- highter ADH (anti-diuretic hormone)- highter

circulating levels increase amount of circulating levels increase amount of reabsorption of waterreabsorption of water

Composition of normal urineComposition of normal urine

pH = 6pH = 6 Water = 93-97%Water = 93-97% Color = clear yellowColor = clear yellow