Chapter 9Chapter 9The Urinary SystemThe Urinary System

Sheila Reyes

Bio 120

The Urinary System is The Urinary System is consists of:consists of:

Two kidneysTwo kidneys Two tubes Two tubes

called ureterscalled ureters A sac called the A sac called the

urinary bladderurinary bladder And another And another

tube called the tube called the urethraurethra

Fig. 1A. Front View of Urinary Tract

Functions of Urinary Functions of Urinary System:System:

Maintains homeostasis of Maintains homeostasis of extracellular fluid by filtering out extracellular fluid by filtering out electrolytes and waste products.electrolytes and waste products.

These organs control the amount These organs control the amount of water and salts that are of water and salts that are absorbed back into the blood and absorbed back into the blood and what is taken out as waste. what is taken out as waste.

This system also acts as a This system also acts as a filtering mechanism for the blood.filtering mechanism for the blood.

KidneysKidneys

Filters the Filters the blood.blood.

Bean-shaped, Bean-shaped, fist sized organs fist sized organs lying on each lying on each side of the side of the lumbar lumbar vertebrae.vertebrae.

Located behind Located behind the peritoneal the peritoneal membrane.membrane.

Fig. 1B. Diagram of a kidney

UretersUreters

Are long, narrow tubes Are long, narrow tubes connecting the kidney to the connecting the kidney to the bladder.bladder.

Urine is removed along each Urine is removed along each ureter by peristalsis, the same ureter by peristalsis, the same type of muscle contraction that type of muscle contraction that moves food through the moves food through the digestive tract.digestive tract.

Empty into the urinary bladder.Empty into the urinary bladder.

Urinary BladderUrinary Bladder

where urine is stored where urine is stored to be released from the to be released from the body.body.

It can hold between It can hold between one half to two cups of one half to two cups of urine before it needs to urine before it needs to be emptied.be emptied.

Everyday about two to Everyday about two to five cups of urine pass five cups of urine pass through the bladder.through the bladder.

Fig. 1C. Urinary Bladder

UrethraUrethra

Tube that carries urine out of the Tube that carries urine out of the body from the urinary bladder.body from the urinary bladder.

Urethral meatus is the external Urethral meatus is the external opening of the urethra.opening of the urethra.

In females, the urethra is 1.6 In females, the urethra is 1.6 inches long.inches long.

In males, the urethra is 7.9 In males, the urethra is 7.9 inches long.inches long.

Urine CultureUrine Culture

a test to find and identify a test to find and identify germs (usually bacteria) germs (usually bacteria) that may be causing a that may be causing a urinary tract infection urinary tract infection (UTI).(UTI).

Urine in the bladder Urine in the bladder normally is sterile-it does normally is sterile-it does not contain any bacteria not contain any bacteria or other organisms (such or other organisms (such as fungi). But bacteria as fungi). But bacteria can enter the urethra and can enter the urethra and cause an infection. cause an infection.

Fig 2A. Urine culture in a specimen cup

A urine culture may be A urine culture may be done to: done to:

Find the cause of a urinary tract Find the cause of a urinary tract infection (UTI). infection (UTI).

Make decisions about the best Make decisions about the best treatment for a UTI. This is called treatment for a UTI. This is called sensitivity testing. sensitivity testing.

Find out whether treatment for a Find out whether treatment for a UTI worked. UTI worked.

Results:Results:

Normal:Normal:No bacteria or other organisms No bacteria or other organisms (such as fungi) grow in the culture. The (such as fungi) grow in the culture. The culture result is culture result is negativenegative..

Abnormal:Abnormal:Organisms (usually bacteria) Organisms (usually bacteria) grow in the culture. The culture result is grow in the culture. The culture result is positivepositive. A count of 100,000 or more . A count of 100,000 or more bacteria per ml of urine may be caused by bacteria per ml of urine may be caused by an infection. A count ranging from 100 to an infection. A count ranging from 100 to 100,000 could be either caused by infection 100,000 could be either caused by infection or by contamination of the sample (you may or by contamination of the sample (you may need a repeat urine culture). If the count is need a repeat urine culture). If the count is 100 or less, infection is unlikely; however, a 100 or less, infection is unlikely; however, a count of 100 or less may also be seen if you count of 100 or less may also be seen if you are already taking antibiotics.are already taking antibiotics.

Urinary Tract Infection Urinary Tract Infection (UTI)(UTI)

A urinary tract infection (UTI) is an A urinary tract infection (UTI) is an infection involving the kidneys, infection involving the kidneys, ureters, bladder, or urethra. These are ureters, bladder, or urethra. These are the structures that urine passes the structures that urine passes through before being eliminated from through before being eliminated from the body. the body.

Simple infections occur in healthy Simple infections occur in healthy urinary tracts and do not spread to urinary tracts and do not spread to other parts of the body. They usually other parts of the body. They usually go away readily with treatment. go away readily with treatment.

Complicated infections are caused by Complicated infections are caused by anatomic abnormalities, spread to anatomic abnormalities, spread to other parts of the body, are worsened other parts of the body, are worsened by underlying medical conditions, or by underlying medical conditions, or are resistant to many antibiotics. They are resistant to many antibiotics. They are more difficult to cure. are more difficult to cure.

Causes of UTI:Causes of UTI:

At least 90% of uncomplicated infections is a type of bacteria At least 90% of uncomplicated infections is a type of bacteria called called Escherichia coliEscherichia coli better know as better know as E. coliE. coli. These bacteria . These bacteria normally live in the bowel (colon) and around the anus. normally live in the bowel (colon) and around the anus.

Conditions that block (obstruct) the urinary tract, such as Conditions that block (obstruct) the urinary tract, such as kidney stones.kidney stones.

Incomplete bladder emptying (for example, spinal cord injury Incomplete bladder emptying (for example, spinal cord injury or bladder decompensation after menopause).or bladder decompensation after menopause).

Women who are sexually active: Sexual intercourse can Women who are sexually active: Sexual intercourse can introduce larger numbers of bacteria into the bladder. introduce larger numbers of bacteria into the bladder. Infection is more likely in women who have frequent Infection is more likely in women who have frequent intercourse. Infection attributed to frequent intercourse is intercourse. Infection attributed to frequent intercourse is nicknamed "honeymoon cystitis." Urinating after intercourse nicknamed "honeymoon cystitis." Urinating after intercourse seems to decrease the likelihood of developing a urinary seems to decrease the likelihood of developing a urinary tract infection. tract infection.

Young children: Young children have trouble wiping Young children: Young children have trouble wiping themselves and washing their hands well after a bowel themselves and washing their hands well after a bowel movement. Poor hygiene has been linked to an increased movement. Poor hygiene has been linked to an increased frequency of urinary tract infections. frequency of urinary tract infections.

Hospitalized patients or nursing home residents: Many of Hospitalized patients or nursing home residents: Many of these individuals are catheterized for long periods and are these individuals are catheterized for long periods and are thus vulnerable to infection of the urinary tract. thus vulnerable to infection of the urinary tract.

Symptoms:Symptoms:

Dysuria: pain or burning during urination Dysuria: pain or burning during urination Frequency: more frequent urination (or Frequency: more frequent urination (or

waking up at night to urinate); often with waking up at night to urinate); often with only a small amount of urine only a small amount of urine

Urgency: the sensation of not being able to Urgency: the sensation of not being able to hold urine hold urine

Hesitancy: the sensation of not being able to Hesitancy: the sensation of not being able to urinate easily or completely (or feeling that urinate easily or completely (or feeling that you have to urinate but only a few drops of you have to urinate but only a few drops of urine come out) urine come out)

Cloudy, bad-smelling, or bloody urine Cloudy, bad-smelling, or bloody urine Lower abdominal painLower abdominal pain Mild fever (less than 101 F), chills, and "just Mild fever (less than 101 F), chills, and "just

not feeling well" (malaise) not feeling well" (malaise)

TreatmentTreatment

Drink plenty of water. Drink plenty of water. Avoid coffee, alcohol, and spicy Avoid coffee, alcohol, and spicy

foods, all of which irritate the foods, all of which irritate the bladder. bladder.

Quit smoking. Smoking irritates Quit smoking. Smoking irritates the bladder and is known to the bladder and is known to cause bladder cancer. cause bladder cancer.

Take a pain-relieving medication. Take a pain-relieving medication. Use a hot-water bottle to ease Use a hot-water bottle to ease

pain. pain. Finish all antibiotic medication Finish all antibiotic medication

even if you are feeling better even if you are feeling better before the medication is gone. before the medication is gone.

Follow your health-care provider's Follow your health-care provider's treatment recommendations. treatment recommendations.

Fig 3A. Urine test for UTI

Chronic Renal FailureChronic Renal Failure

Can become irreversible Can become irreversible renal failure.renal failure.

Waste products are not Waste products are not filtered resulting in filtered resulting in uremia and death.uremia and death.

is a worldwide public is a worldwide public health problem and is health problem and is now recognized as a now recognized as a common condition that common condition that is associated with an is associated with an increased risk of increased risk of cardiovascular disease cardiovascular disease and chronic renal failure and chronic renal failure

Fig 4A. A patient undergoing hemodialysis

Stages of CRF According to Stages of CRF According to K/DOQI guidelines:K/DOQI guidelines:

Stage 1: Kidney damage with normal or Stage 1: Kidney damage with normal or increased GFR (>90 mL/min/1.73 m2)increased GFR (>90 mL/min/1.73 m2)

Stage 2: Mild reduction in GFR (60-89 Stage 2: Mild reduction in GFR (60-89 mL/min/1.73 m2)mL/min/1.73 m2)

Stage 3: Moderate reduction in GFR Stage 3: Moderate reduction in GFR (30-59 mL/min/1.73 m2)(30-59 mL/min/1.73 m2)

Stage 4: Severe reduction in GFR (15-Stage 4: Severe reduction in GFR (15-29 mL/min/1.73 m2)29 mL/min/1.73 m2)

Stage 5: Kidney failure (GFR <15 Stage 5: Kidney failure (GFR <15 mL/min/1.73 m2 or dialysis)mL/min/1.73 m2 or dialysis)

Causes of CRF:Causes of CRF:

Vascular diseaseVascular disease - Renal artery stenosis, atheroemboli, - Renal artery stenosis, atheroemboli, hypertensive nephrosclerosis, renal vein thrombosis hypertensive nephrosclerosis, renal vein thrombosis

Primary glomerular diseasePrimary glomerular disease - Membranous - Membranous nephropathy, immunoglobulin A (IgA) nephropathy, focal nephropathy, immunoglobulin A (IgA) nephropathy, focal and segmental glomerulosclerosis (FSGS) and segmental glomerulosclerosis (FSGS)

Secondary glomerular diseaseSecondary glomerular disease - Diabetes mellitus, - Diabetes mellitus, systemic lupus erythematosus, rheumatoid arthritis, mixed systemic lupus erythematosus, rheumatoid arthritis, mixed connective tissue disease, scleroderma, Goodpasture connective tissue disease, scleroderma, Goodpasture syndrome, Wegener granulomatosis, mixed syndrome, Wegener granulomatosis, mixed cryoglobulinemia, postinfectious glomerulonephritis, cryoglobulinemia, postinfectious glomerulonephritis, endocarditis, hepatitis B and C, syphilis, human endocarditis, hepatitis B and C, syphilis, human immunodeficiency virus (HIV), parasitic infection immunodeficiency virus (HIV), parasitic infection

Tubulointerstitial diseaseTubulointerstitial disease - Drugs (eg, sulfa, - Drugs (eg, sulfa, allopurinol), infection (viral, bacterial, parasitic), Sjögren allopurinol), infection (viral, bacterial, parasitic), Sjögren syndrome, chronic hypokalemia, chronic hypercalcemia, syndrome, chronic hypokalemia, chronic hypercalcemia, sarcoidosis sarcoidosis

Urinary tract obstructionUrinary tract obstruction - Urolithiasis, benign prostatic - Urolithiasis, benign prostatic hypertrophy, tumors, retroperitoneal fibrosis, urethral hypertrophy, tumors, retroperitoneal fibrosis, urethral stricture, neurogenic bladder stricture, neurogenic bladder

Treatment:Treatment:

Controlling blood pressure is the key to delaying Controlling blood pressure is the key to delaying further kidney damage. further kidney damage.

Do not smoke. Do not smoke. Eat meals that are low in fat and cholesterol Eat meals that are low in fat and cholesterol Get regular exercise (talk to your doctor or nurse Get regular exercise (talk to your doctor or nurse

before starting). before starting). Take drugs to lower your cholesterol, if necessary. Take drugs to lower your cholesterol, if necessary. Keep your blood sugar under control. Keep your blood sugar under control. Special medicines called phosphate binders, to help Special medicines called phosphate binders, to help

prevent phosphorous levels from becoming too high prevent phosphorous levels from becoming too high Treatment for anemia, such as extra iron in the diet, Treatment for anemia, such as extra iron in the diet,

iron pills, special shots of a medicine called iron pills, special shots of a medicine called erythropoietin, and blood transfusions erythropoietin, and blood transfusions

Extra calcium and vitamin D (always talk to your Extra calcium and vitamin D (always talk to your doctor before takin doctor before takin

CystoscopyCystoscopy

the use of a scope the use of a scope (cystoscope) to (cystoscope) to examine the examine the bladder.bladder.

This is done either This is done either to look at the to look at the bladder for bladder for abnormalities or to abnormalities or to help with surgery help with surgery being performed on being performed on the inside of the the inside of the urinary tract urinary tract (transurethral (transurethral surgery). surgery).

Fig 5A. Use of Cytoscope to examine the bladder

Risks:Risks:

Generally a safe procedure. Generally a safe procedure. Serious complications are rare.Serious complications are rare. There is the risk of infection, bleeding, and There is the risk of infection, bleeding, and

complications from the anesthesia. complications from the anesthesia. Antibiotics are used before the surgery to reduce the Antibiotics are used before the surgery to reduce the

incidence of urinary tract infection.incidence of urinary tract infection. Bleeding is generally controlled during the Bleeding is generally controlled during the

procedure with the use of cautery.procedure with the use of cautery. Risk of perforation or a tear. Risk of perforation or a tear. Creates scar tissue.Creates scar tissue. Men can sometimes experience pain and swelling in Men can sometimes experience pain and swelling in

the testicles after an extensive procedure. This is the testicles after an extensive procedure. This is called epididymitis.called epididymitis.

Urinary retention (inability to urinate) can occur after Urinary retention (inability to urinate) can occur after cystoscopy. cystoscopy.

Recovery:Recovery:

Most people undergoing cystoscopy Most people undergoing cystoscopy will be able to go home the same day will be able to go home the same day as the procedure. as the procedure.

Recovery depends on the type of Recovery depends on the type of anesthesia. If only local anesthetic is anesthesia. If only local anesthetic is used, you can go home immediately.used, you can go home immediately.

For other people, a recovery period For other people, a recovery period of 1-4 hours is necessary. During this of 1-4 hours is necessary. During this observation period, the anesthetic will observation period, the anesthetic will wear off, and you will need to be able wear off, and you will need to be able to urinate prior to leaving. to urinate prior to leaving.

References:References:

Webmd.comWebmd.com Emedinehealth.comEmedinehealth.com Essentials of Medical Essentials of Medical

Terminology 3Terminology 3rdrd Ed. ( Juanita Ed. ( Juanita Davies)Davies)