Urinary SystemUrinary System

IntroductionIntroduction

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

AnatomyAnatomy• 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)

AnatomyAnatomy (Continued)(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 Anatomy (Continued)(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 KidneysFunction 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 Function of the Kidneys (Continued)(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 FunctionNephron Function

• Nephrons: work of separation and recycling in kidney

• Each kidney contains millions of nephrons

Tubular SecretionTubular 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 Conditions Affecting the Urinary SystemUrinary System

Anuria Lack of urine: less than 100 mL over 24 hours

Cystitis Inflammation of the bladder

Edema Increase in fluid in cells, tissues, and/or cavities

Hyperkalemia Excessive increase in potassium in the blood

Hypokalemia Excessive decrease in potassium in the blood

Incontinence Lack of control of urination or feces

Oliguria Little urine output: Between 100 mL and 400 mL over 24 hours

Conditions Affecting the Urinary Conditions Affecting the Urinary System System (Cont)(Cont)

Polyuria Excessive or large volumeof urine within a certain period of time

Pyelonephritis Inflammation of the kidney

Renal failure Kidney no longer functions

Uremia Excess urea in the blood

Urethritis Inflammation of the urethra

Urolithiasis Kidney stones made of calcium or salts

Urinary tract Bacterial infection of the infection (UTI) urinary tract

RENAL DISORDERSRENAL 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 InfectionsUrinary 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 Treatments for Urinary System ConditionsConditions

• 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

HemodialysisHemodialysis• 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

http://www.learnerstv.com/video/Free-video-Lecture-6327-Nursing.htm

Peritoneal DialysisPeritoneal 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 EdemaPharmacological 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 UTIsTreatment 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