Genitourinary System:

Urinary system
Background information-
Maintains Homeostasis
Regulates water, electrolytes and acid base balance
Excretes waste
Removes hormones and drugs
Secretes erythropoietin
Activate vitamin D
Regulate blood pressure through the renin-angiotensin-aldosterone
In the male the GU system has a reproductive role

*Kidneys have excretory and nonexcretory functions:

Excretory removes wastes - urea, creatinine, uric acid, phosphates, sulfates, nitrates, and phenols along with excess fluid and electrolytes.

Nonexcretory - functions include the secretion of renin, erythropoietin, metabolism of carbohydrates and regulation of vitamin D.

GU composed of kidneys, ureters, bladder and urethra.
2 fist sized bean shaped kidneys situated on the posterior abdominal wall behind the peritoneum.
Kidneys are covered by a fibrous capsule
Each kidney has over a million nephrons
Kidneys filter large volumes of fluid from blood
Cells and protein remain in the blood
Reabsorption of nutrients and electrolytes uses active transport
Water is reabsorbed by osmosis
Hormones control the reabsorption of fluid and electrolytes
Antidiuretic hormone controls reabsorption of water
Aldosterone controls sodium reabsorption and water
Atrial natriuretic hormone from heart reduces Na+ and water reabsorption
Scar tissue can interfere with blood and filtrate flow
Two arteries and two sets of capillaries in each nephron
If blood flow is impaired renin angiotensin mechanism activated to restore BP

*Blood pressure related to kidney function and it is elevated w/ renal disease
Once filtate is processed in the tubules and collecting ducts = urine

Bladder close to anterior abdominal wall and as child matures, settles into the pelvis
Composed of smooth muscle
Mucosa lining continuous allowing spread of infection
Micturition (urination, voiding) stimulated by increased pressure

Kidneys produce urine --->
Urine goes through ureters to the bladder --->
Exists the body via the urethra --->

Kidneys in children are more susceptible to injury
Incontinence – loss of voluntary control of bladder
Enuresis involuntary urination after bladder control achieved
Stress incontinence urogenital diaphragm weakened
Overflow incontinence – incompetent bladder spincter
Neurogenic bladder – spastic, flaccid, CNS interruption, spinal cord injury
Retention is the inability to empty the bladder
Catheter tube inserted into urethra

Diagnostic tests
Appearance, clear, cloudy, color, odor
Checks for blood - hematuria
Protein – proteinuria
Bacteria – bacteriuria, pus – pyuria
Casts - cells
Specific gravity – ability to concentrate urine
Glucose, ketones
Culture and sensitivity: identify causative infectious microbe

Blood tests:
Elevated serum urea indicates failure to excrete nitrogen wastes
Metabolic acidosis – V serum ph, V serum bicarbonate, V filtration rate
Anemia – decreased erythropoietin , bone marrow depression
Electrolytes –
Antibody level ASO - antistreptolysin levels from strep infection
Renin levels cause of hypertension
Clearance tests –
Radiographic – CT, MRI, IVP, cystoscopy, biopsy

Diuretic drugs
“Water pills”
Used to remove excess sodium ions and water, increases output, decreases edema
Most common Hydro, Diuril, Furosemide, lasix – inhibits NaCl absorption
Major side effect – loss of electrolytes causing muscle weakness, cardiac irreg.
Need to take K+ or bananas
K+ sparing diuretics – Aldactone
Observe for orthostatic hypotension

Kidney Nephrons

Renal failure

Artificial kidney
Can function w/ ½ of one kidney
Used for those w/ acute renal failure, end stage renal disease, failing transplant
2 forms
*Hemodialysis or peritoneal

Hemodialysis: blood moves from shunt in arm to machine where a semi permeable membrane separates the blood from the dialysate. Heparin or another anticoagulate is used to decrease the risk of clots. Required 3xs per week for 3-4 hours

Peritoneal dialysis – dialysate id infused and peritoneal membrane acts as the filter
Later fluid is removed. Takes longer, risk of infection

Often dialysis patients are on prophylactic antibiotics

Kidney dialysis

Women more susceptible due to short urethra, e coli often offending organism
Imp. to clean front to back, watch bubble baths
Older men with prostatic hypertrophy, retention
Elderly incomplete emptying, decreased fluid intake
Renal calculi, catheters, trauma, bacteria

Bladder wall, urethra, inflamed, red, swollen
Bladder wall irritated, hyperactive
Dysuria – painful urination
Nocturia – need to void at night
Systemic signs - fever, malaise, nausea
U/A : urine cloudy, bacteria, hematuria

One or both kidneys may be involved
Purulent exudate fills the kidney pelvis
Exudate can obstruct flow
Scarring can result
Hydronephrosis – fluid filled

Infection in kidneys and bladder so cystitis symptoms
Dull aching pain flank area, pressure of edema against renal capsule
Marked systemic signs
U/A similar

Increase fluid intake
Antibacterials – Bactrim, Furadantin
Pockets of infection can persist retest in 4-6 weeks
Chronic pyelonephritis scarring, damage continued infection
Cranberry juice – tannin reduces e coli’s ability to stick to bladder wall

Glomerulonephritis (Acute poststreptococcal glomerulonephritis) APSGN
Occurs 10 days to 2 weeks after infection
The antistrep antibodies create an antigen-antibody complex (type III hypersensitivity rx that lodges in the glomerular capillaries, activates the complement system to cause an inflammatory response

This causes increased capillary permeability, results in leakage of protein and large numbers of erythrocytes….blood

Dark, smokey, coffee or tea colored urine
Facial, periorbital edema
Blood pressure increased due to increased rennin, decreased GFR
Flank or back pain as kidney swells and stretches the capsule
Malaise, fatigue, headache, anorexia, nausea
Output decreases as GFR deceases

Blood tests:
Elevated serum urea, creatinine
Antistreptolysin titer and ASK are high
Metabolic acidosis
Urinalysis – proteinuria, gross hematuria

Na+ restrictions
Glucocorticoids to decrease inflammation
Prophylactic antibiotics

Nephrotic syndrome
Other systemic diseases may relate
Abnormal glomerular capillaries, increased permeability allowing albumin out
Hypoalbuminemia, generalized edema
BP low or normal due to hypovolemia
Decreased blood volume increases aldosterone increases edema
High levels of cholesterol in blood (response of liver to protein loss?)


U/A frthy urine with high protein levels
Massive edema, weight gain pallor
Impairs appetite, breathing, activity
Skin susceptible to breakdown

ACE inhibitor may decrease protein loss
Antihypertensive therapy may be required
Antilipemic therapy required in some
Tend to recur
Na+ intake may be restricted but protein increased

Urolithiasis kidney stones:
Excessive amounts of insoluble salts, w/ decreased fluid intake
Once solid material tends to build on ‘nidus’

Can start from cell debris
Immobility, stasis contributing factor
Usually cause symptoms when obstruct flow
Cause infection due to irritation, injury, hydronephrosis
75% composed of calcium salts,
Examine to determine cause
Calcium stones due to hypercalcemia, stones form readily when urine is alkaline
Uric acid stones from hyperuricemia due to gout, chemotherapy

Asymptomatic unless frequent infections
Flank pain distention of capsule
Obstruction of ureter – renal colic
Severe pain, nausea, vomiting, cool moist skin

Small stones passed and examined
Large stones shock wave lithotripsy


Wilms Tumor Nephroblastoma

Most common renal and intra abdominal tumor of children. Commonly discovered at approximately age three, almost always by age 5. More common in AA. Slightly more common in boys. 1-2.5% have a familiar history. Favors the left kidney although both can be involved.

Most children present with abdominal swelling.
Firm, nontender and confined to one side.
Other symptoms common with a Wilms tumor include: hematuria, fatigue, malaise, hypertension, weight loss and fever.

Diagnostic tests:
Abdominal ultrasound,
Abdominal and chest CT,
Biochemical tests, blood work, urinalysis.
Possibly an inferior venacaogram to see if there is any involvement close to the vena cava and possibly a bone marrow aspiration if metastasis is suspected. Fortunately this is rare.

The tumor can be staged I-V. Survival rates are 90% for grades I and II.

*Do not palpate the abdomen! This can lead to shedding and spreading of cells.

Radiotherapy and chemotherapy are usually initiated after surgery. Occassionally these are instituted prior to surgery if the tumor is large or both kidneys are involved.

Chronic renal failure


Gould, B. E., & Dyer, R. M. (2011). Pathophysiology for the health professions (4 ed.). St. Louis, Missouri: Saunders Elsevier.

Story, L. (2012). Pathophysiology: A practical approach. Sudbury, MA: Jones & Bartlett Learning .


Anatomy of the Kidney

Kidney nephrons


Nephrotic syndrome

Kidney stones