The Urinary System

Functions

  • Homeostasis

    • Urinary system maintains the proper balance of water, salts, and acids in the body by filtering the blood through the kidneys

  • Filters waste from protein metabolism and muscle metabolism

  • Converts waste products and excess water into urine

Homeostasis

  • Process by which the body maintains a constant internal environment

Anatomy of Urinary System

  • 2 kidneys

  • 2 ureters

  • 1 bladder

  • 1 urethra

  • 1 urethra meatus

Kidneys

  • Bean shaped organ about the size of a fist

  • Located in the retroperitoneal space

  • Filter 200 quarts of blood every day to remove waste products and excess water

    • Waste product is urine (95% water and 5% waste)

    • Filters all 8 liters of our blood 20-25 times/day

  • Produces hormones that have an effect on B/P, RBC production and vitamin D

  • Consists of two parts:

    • Renal cortex: outer region of kidney

      • Nephrons: filters fluid

        • Microscopic functional units of the kidney

        • Produce the urine

        • Each one contains glomerulus, bowman’s capsule, and loop of henley

    • Medulla: inner region of kidney

Production of Urine

  1. Blood enters kidney thru renal artery and goes to the nephrons

  2. Filtered by the glomerulus

  3. Now-filtered blood returns to blood stream thru renal vein

    • Blood cells and proteins remain in blood

  4. Whatever was filtered out goes to the renal tubules where a lot of water, sugar, and salts are returned to blood stream

  5. Remaining waste products are turned into urine and transported to renal pelvis and eventually to ureters

Ureters

  • 10-12 inch long tubes that transport urine from kidney to bladder

    • Use peristalsis

    • Connecting tubes

  • Urine drains from ureters to bladder through ureteral orifices

Bladder

  • Oval hollow organ; reservoir for urine

  • Contains rugae

    • Folds that allow bladder to expand and contract

  • Holds approx. 1 cup of urine before it sends “urge” signal to brain

Urethra & Urethral Meatus

  • Urethra

    • Transports urine from bladder to outside of the body

      • Females: 1 ½ inches long

      • Males: 8 inches long

  • Urethral meatus

    • External opening of the urethra

  • Urination is AKA voiding or micturition

Diseases of Urinary System

Renal Pathology

Renal Failure

  • Uremia

    • Uremic poisoning kidney function compromised and waste products are retained in the blood

  • Acute renal failure

    • Sudden onset of uremia

    • Can be fatal

    • Cause could be from kidneys that are not receiving enough blood to filter from dehydration, low blood pressure or low blood volume from injury

  • Chronic renal failure

    • Progressive loss of renal function over months or years

      • Diabetes, high blood pressure, family history of renal disease

      • Build up of waste products can lead to heart attacks or strokes

  • End-stage renal disease

    • Final stage of chronic kidney disease

    • Fatal without dialysis or a kidney transplant

Nephrotic Syndrome

  • Group of conditions in which excessive amount of protein are lost through the urine

  • Usually due to damaged glomeruli

  • Symptoms include:

    • Edema: excessive fluid accumulation in body tissues

    • Hyperproteinuria: increased protein in the urine

    • Hypoproteinuria: decreased protein in the blood

  • Causes are diabetes mellitus, infection, or kidney disorders

Kidney Conditions

  • Hydronephrosis

    • Swelling of kidneys due to backup of urine from a blockage

  • Glomerulonephritis

    • Inflammation of the glomeruli that causes RCs and protein to leak into the urine

  • Nephroptosis

    • Prolapse of a kidney into the pelvic area when the patient stands

  • Polycystic Kidney Disease

    • Genetic

    • Growth of numerous fluid-filled cysts in the kidneys

    • Cysts slowly replace much of the mass of the kidney leading to kidney failure

  • Wilms tumor

    • Rare malignant kidney tumor

    • Found in young children

    • High cure rate if treated early

Nephroliths

  • Abnormal mineral deposit

  • Vary in size from too-small-to-notice → marble-like and very painful

  • Nephrolithiasis

    • Presence of kidney stones

    • Named based on where they are lodged (e.g., cystolith)

  • Renal colic

    • Acute in pain kidneys due to passage of a nephrolith

Treatments of Nephroliths

  • Most small stones pass out of the urinary tract on their own within a few weeks

  • Extracorporeal Shockwave Lithotripsy

    • Most common treatment, high energy ultrasonic waves traveling through water or gel break up the stone is which then

  • Percutaneous nephrolithotomy

    • Surgical removal of a stone through a small incision in the back

    • Used if ESWL is unsuccessful, there is an infection, or if the stone is really big

  • Ureteroscopy

    • Treatment of a stone lodged near the ureter

    • Ureteroscope is inserted through the urethra, thru the bladder and into the ureter

    • Can remove the stone whole, but if too big, can be cut with a laser

Ureters Pathology

  • Hydroureter

    • Blocked ureter causes distention with urine

    • Always accompanies hydronephrosis

  • Ureterectasis

    • Distention of a ureter

  • Ureterorrhagia

    • Discharge of blood from the ureter

Bladder Pathology

  • Cystocele

    • Prolapsed bladder

    • Hernia of the bladder through the vaginal wall

    • Cause is pregnancy/childbirth

  • Interstitial cystitis

    • Chronic inflammation within the walls of the bladder

  • Vesicovaginal fistula

    • Abnormal opening between bladder and vagina

    • Cause was prolonged labor/childbirth

      • Fistula: abnormal opening between two internal organs

  • Treatments for incontinence due to cystocele would be pessary ring or bladder neck suspension

  • Neurogenic bladder

    • Urinary problem caused by interference with the normal nerves associated with urination

    • Bladder may empty spontaneously

    • Bladder may not empty at all or may empty incompletely resulting in retention or overflow leakage

      • Causes are nervous system tumor, trauma, neuropathy, or an inflammatory condition

Prostate Gland Pathology

Prostate Gland

  • Benign Prostatic Hyperplasia (BPH)

    • Benign prostatic hypertrophy

      • Enlarged prostate

      • Usually in men >50

      • Makes urination difficult

  • Prostatism

    • Disorder from the compression or obstruction of the urethra due to BPH

Enlarged Prostates and Urination

  • Overflow incontinence

    • Continuous leaking from the bladder due to being too full or not emptying completely

    • Prevalent in older men with enlarged prostates

  • Urinary hesitancy

    • Difficulty in starting a urinary stream

    • Common in older men with prostate problems

    • In younger people, hesitancy may be caused by bashful bladder syndrome - inability to urinate near another person

  • Urinary retention (ischuria)

    • Inability to completely empty the bladder when urinating

    • Also associated with enlarged prostates

  • Treatments for enlarged prostrate include alpha blockers or proton pump therapy

Urethra Pathology

  • Urethrorrhagia

    • Bleeding from the urethra

  • Urethrostenosis

    • Narrowing of the urethra

    • Almost exclusive to men

    • Scar tissue from infection or injury

  • Epispadias

    • Male: urethral opening on the upper surface of the penis

    • Female: urethral opening near the clitoris

  • Hypospadias

    • Male: urethral opening on ventral of penis

    • Female: urethral opening in the vagina

  • Urinary Tract Infections (UTI)

    • Usually begins in the bladder but can affect all parts of the urinary system

    • Usually bacterial (E. coli)

    • More common in women because their urethra is shorter and closer to the rectum

Terms Associated with Urination

  • Anuria

    • Absence of urine

  • Oliguria

    • Scanty urination

  • Polyuria

    • Excessive urination

  • Diuresis

    • Increased output of urine

  • Dysuria

    • Difficult or painful urination

  • Nocturnal enuresis

    • Involuntary discharge of urine

    • AKA bed wetting

  • Nocturia

    • Frequent/excessive urination at night

  • Incontinence

    • Inability to control the excretion of urine, feces or both (urinary incontinence, fecal incontinence)

    • Stress incontinence: Incontinence due to physical stress such as running, lifting, sneezing, laughing, or coughing

      • More common in women than men

  • Overactive bladder

    • Muscles of bladder contract involuntarily resulting in urinary frequency or accidental urination

    • Related to excessive caffeine or alcohol consumption, UTIs neurological disease, bladder/prostate problems

Diagnostic Procedures

  • Urinalysis

    • Examination of urine to determine the presence of abnormal elements

  • Cystoscopy

    • Visual exam of the bladder with an endoscope

    • Specialized endoscopes that can remove tumors or reduce an enlarged prostate

Catheterization

  • Urinary catheterization

    • Insertion of a tube into the bladder

    • Can be used to get a sterile urine specimen

    • To drain from the bladder when the patient is unable to urinate normally

    • Can be used to place fluids into the bladder (like chemotherapy medications or contrast mediums

Radiographic Exams

  • Cystography

    • X-ray exam of the bladder after a contrast medium is instilled via a urethral catheter

  • Voiding cystourethrography

    • Procedure using a fluoroscope is used to examine the flow of urine from the bladder thru the urethra

  • Intravenous pyelogram (IVP)

    • Radiographic study of kidneys and ureters

    • Contrast medium put in an IV

    • Can see stones, infections, enlarged prostate, tumors, injuries

  • KUB (kidney, ureters, bladder)

    • AKA flat-plate of the abdomen

    • No contrast medium used

    • Shows bowel obstructions, stones

    • Does not show ureters

Dialysis

  • Dialysis

    • Procedure to remove waste products and excess water from the blood of a patient whose kidneys no longer function

    • Hemodialysis: waste products are filtered directly from the patient’s blood using an external hemodialysis unit (artificial kidney)

    • Peritoneal dialysis: the lining of the peritoneal cavity acts as a filter to remove waste from the blood

Kidney Procedures

  • Nephrolysis

    • Surgical freeing of a kidney from an adhesion

  • Nephropexy

    • Surgical fixation of nephroptosis

  • Nephrostomy

    • Placement of a catheter to maintain an opening from the pelvis of the kidney to the exterior of the body

    • Used for draining urine from kidneys with hydronephrosis or for gaining access to kidneys for diagnostic procedures

  • Pyeloplasty

    • Surgical repair of the ureter and renal pelvis

  • Pyelotomy

    • Surgical incision into the renal pelvis

    • To correct obstructions such as a stone lodged between the renal pelvis and the ureter

Urinary Bladder

  • Neobladder

    • Replacement of a missing bladder created by using about 20 inches of the small intestines

  • Ileal conduit

    • AKA a type of ileostomy

    • Use of a small piece of intestine (ileum)

    • to convey urine from the ureters to a stoma in the abdomen

  • Cystopexy

    • Surgical fixation of the bladder to the abdominal wall

Urethral Procedures

  • Meatotomy

    • Surgical incision in the urethral meatus to enlarge the opening

  • Urthropexy

    • Surgical fixation of the urethra to nearby tissue

    • Often performed to correct urinary stress incontinence

  • Urethrotomy

    • Surgical incision into the urethra for relief of a stricture

Prostate Treatments

  • Ablation

    • Removal of a body part or the destruction of its function thru surgery, hormones, drugs, heat, chemicals, electrocautery, etc.

  • Prostatectomy

    • Surgical removal of part or all of the prostate gland

  • Transurethral prostatectomy

    • Removal of excess tissue from and enlarged prostate using a resectoscope

Urinary Incontinence Treatment

  • Kegel

    • Pelvic muscle exercises used to strengthen the muscles of the pelvic floor

  • Bladder retraining

    • Behavior therapy in which the patient learn to urinate on a schedule

    • Useful for patients suffering from urge incontinence