Urinary System

Introduction Kidneys and lungs: two systems that both help and create homeostasis (balancing compositions of fluids and tissues within body system

Anatomy Kidneys: located inside upper abdominal cavity on either side of vertebrae Renal fascia: fibrous connective tissue that holds kidneys stationary Kidney: bean-shaped with hilus (indentation)

Anatomy (Continued) Blood filtered in kidney Sodium, chloride reabsorbed into body and circulatory system Renal artery: where blood enters kidney Renal vein: returns blood to body after the filtering process

Anatomy (Continued) Ureter carries waste removed from blood to bladder, where it is stored for excretion Bladder - holding tank that can expand Urine eliminated through urethra - tube leading from bladder to outside of body

Function of the Kidneys Bladder holds up to 1000 mL of urine Urine contains urea; form of nitrogen that changes to ammonia Kidneys balance fluid content of body: –Water –Blood –Plasma

Function of the Kidneys (Continued) Kidneys balance and eliminate ions within blood (such as Cl, K, and Na) Imbalance of ions in blood: –Acidosis: too many free hydrogen ions –Alkalosis: too many hydroxide ions –Urine pH 4 to 5 –Blood pH 7.4 Blood urea nitrogen (BUN) test determine levels of acid in patient’s system

Nephron Function Nephrons: work of separation and recycling in kidney Each kidney contains millions of nephrons

Tubular Secretion Ions, toxins, water are secreted into collecting duct Secretion and elimination of weak acids (aspirin, penicillin) and weak bases (narcotic analgesics, antihistamines) Hydrogen ions combine to form bicarbonate Released into bloodstream to regulate overall pH of body, maintaining homeostasis Buffer can bind or release hydrogen to balance blood pH

Conditions Affecting the Urinary System AnuriaLack of urine: less than 100 mL over 24 hours CystitisInflammation of the bladder EdemaIncrease in fluid in cells, tissues, and/or cavities HyperkalemiaExcessive increase in potassium in the blood HypokalemiaExcessive decrease in potassium in the blood IncontinenceLack of control of urination or feces OliguriaLittle urine output: Between 100 mL and 400 mL over 24 hours

Conditions Affecting the Urinary System (Cont) PolyuriaExcessive or large volume of urine within a certain period of time PyelonephritisInflammation of the kidney Renal failureKidney no longer functions UremiaExcess urea in the blood UrethritisInflammation of the urethra UrolithiasisKidney stones made of calcium or salts Urinary tractBacterial infection of the infection (UTI)urinary tract

RENAL DISORDERS RENAL FAILURE: Caused by accidents, toxic agents, genetic diseases, illnesses EDEMA: Caused by congestive heart failure (CHF), hypertension KIDNEY STONES: Usually found in persons between ages 20 and 55, but can affect anyone

Urinary Tract Infections Nosocomial infections: picked up in hospital UTI: common nosocomial; results from catheterization or cystoscopic examinations Pyelonephritis: kidney infection Cystitis: bladder infection

Treatments for Urinary System Conditions Dialysis is only alternative when too much kidney function lost, transplant not possible, or has end-stage renal disease Dialysis: cleansing of blood; replaces normal kidney function of removing wastes and balancing fluids Two methods: hemodialysis, peritoneal dialysis

Hemodialysis Patient: –Visits clinic or hospital for treatment –Hooks up to machine by vein shunt Mechanical filtration system cleanses blood Treatment time: 5 hours 2-3 times a week

Peritoneal Dialysis Patient is hooked up to bag of osmotic solution via catheter Catheter is implanted into abdominal cavity Osmotic solution flows into peritoneal cavity Peritoneal Dialysis Video

Pharmacological Treatment of Edema Main drugs are: –Diuretic thiazides, thiazide-like agents Increase urinary excretion of sodium and chloride ions equally Inhibit normal process of reabsorption with ascending tubule following loop of Henle and distal tubules –Loop diuretics Inhibit reabsorption of sodium and chloride in proximal convoluted tubule, distal convoluted tubule, loop of Henle –Potassium-sparing diuretics Work primarily in distal convoluted tubule

Treatment of UTIs UTI’s: most common cause bacterial infections Women more susceptible due to shorter urethra Catheterization can also cause Kidney infection - glomerulonephritis, pyelonephritis Bladder infection - cystitis Antibiotics used to treat