11 - Urinary System

Kidneys structure and function

Primary functional organs of the urinary system which maintain proper balance of water and electrolytes in the body and filter and remove urea and other waste products from the blood through urine formation. Each kidney comprises an outer layer, the
renal cortex, and an inner layer, the renal medulla. Blood enters the kidney through the renal artery.

Renal artery

Entry point for blood in the kidneys. Branches into smaller and smaller arteries, eventually leading to microscopic filtering units called nephrons.

Nephron

Microscopic functional unit of the kidney which forms urine in renal corpuscles and tubules by process of filtration, reabsorption, and
secretion.

Renal corpuscle

The site of blood filtration in the nephron and consists of the glomerulus and Bowman capsule

Glomerulus

A cluster of capillaries at the beginning of a nephron. Waste-containing fluids (filtrate) are absorbed into Bowman capsule and filtrate flows from the capsule into the renal tubule

Renal tubule

Urine formation is completed in the tubules. Urine then flows from renal tubule to the renal pelvis. Each renal pelvis narrows to form a ureter.

Ureter

Approximately 12-inch-long tube that connects renal pelvis of the kidney to the bladder. When muscles of ureters contract, urine is pushed from the kidneys into the urinary bladder.

Bladder

Hollow, muscular sac in pelvic cavity which serves as a temporary reservoir for urine. Expands as urine collects; contracts when
urine is excreted.

Urethra

Tube extending from the bladder to the external opening, or urinary meatus. Serves as a passageway for excretion of urine from the bladder.

Process of excreting urine

Voiding or micturition

Name four organs of the urinary system

Kidneys, ureters, bladder, and urethra

What is the name of the structure that stores urine until it is voided?

Urinary bladder

What is the main function of the kidneys?

Remove toxic products from blood by forming urine

What structure in the nephron forms urine?

renal tubule

Urine is transported from the kidneys into the urinary bladder via the ____.

ureters

Urine is formed through the process of filtration, reabsorption, and _____.

secretion

nephr/o, ren/o

kidney

pyel/o

renal pelvis

ureter/o

ureter

cyst/o, vesic/o

bladder

ur/o, urin/o

urine, urinary tract

urethr/o

urethra

meat/o

meatus, opening

glomerul/o

glomerulus

-emia

blood

-iasis

abnormal condition (produced by something specified)

-lysis

separation; destruction; loosening

-pathy

disease

-pexy

fixation (of an organ

-ptosis

prolapse, downward displacement

-tripsy

crushing

cystoscope

instrument to examine the bladder

pyelitis

inflammation of the renal pelvis

ureterectasis

expansion of the ureter

urethrostenosis

narrowing or stricture of the urethra

meatotomy

incision of the meatus

lithotripsy

crushing of a calculus or stone

glomerulonephritis

inflammation of the glomerulus and kidney

nephropexy

fixation of a kidney

polyuria

excessive urination

oliguria

scanty urine

urolith

stone or calculus in urinary tract

pyelopathy

disease of the renal pelvis

nephroma

tumor of the kidney

hematuria

urine with blood

pyuria

urine with pus

End-Stage Renal Disease (ESRD) signs and symptoms

Irreversible stage with gradual, progressive deterioration of kidney
function. Kidneys lose ability to excrete nitrogenous end products of metabolism. Progressive weakness, anorexia, diarrhea, pruritus, and polyuria. Severity of signs and symptoms varies depending on extent of renal damage and remaining function. Usually the result of chronic renal failure (CRF), the gradual, progressive deterioration of kidney function to the point that the kidneys cannot sustain their necessary day-to-day activity. Affects all systems.

End-Stage Renal Disease (ESRD) treatment

Dietary restriction of protein, sodium, and potassium intake. Antiemetics for nausea. Control of hypertension. Dialysis. Renal transplantation in severe cases.

Renal Calculi signs and symptoms

Concentration of mineral salts in the renal pelvis, in the calices of the kidney, or in the urinary tract. Patients with renal calculi may remain asymptomatic for long periods. If stone or calculus fragment lodges in a ureter, there may be intense pain and urinary urgency. If calculi are in the renal pelvis and calices, pain is duller and more constant. Back pain and severe abdominal pain may occur. Other symptoms include nausea, vomiting, chills and fever, hematuria, and abdominal distention.

Renal Calculi treatment

Remove stones and prevent new formations. Enhance elimination of stones and increase fluid intake. Small stones pass spontaneously without treatment. Large stones may require surgical intervention. Antibiotics may be prescribed if calculus buildup is due to bacterial infection. Strong analgesics are prescribed for relief of intense pain. Ultrasound is used to locate and monitor calculi as they are being destroyed.

nephralgia or nephrodynia

pain in the kidney area

dysuria

painful or difficult urination

Hydronephrosis signs and symptoms

Distention of renal pelvis and calices caused by pressure from accumulating urine. Pressure impairs and may eventually interrupt kidney function. If obstruction is above bladder opening, only one kidney may be affected, and the person may be asymptomatic for a prolonged period. If both kidneys are affected, symptoms may include intense pain, nausea, vomiting, oliguria or anuria, and hematuria.

Hydronephrosis treatment

Remove obstruction, prevent complications, and treat underlying
disorders. Catheterization for immediate relief of urinary pressure.
Analgesics may be prescribed. Antibiotics are required if infection occurs. Surgery if needed to dilate a ureteral stricture.

anuria

lack of urination

nephromegaly

enlargement of a kidney

pyeloplasty

surgical repair of the renal pelvis

azoturia

increase of nitrogenous substances, especially urea, in urine

diuresis

increased formation and secretion of urine

hypospadias

abnormal congenital opening of the male urethra on the undersurface of the penis

polycystic kidney disease

hereditary condition in which the kidneys are enlarged and contain many cysts that develop over time, requiring dialysis or kidney transplantation

uremia

increase in concentration of urea and other nitrogenous wastes in the blood

Wilms tumor

malignant neoplasm of the kidney that occurs in young children, usually before age 5

Cystoscopy

Examination of urinary bladder. Done to perform, remove tumors or polyps or obtain evidence of a pathology

Bladder ultrasonography

High-frequency sound waves produce images of the bladder. Determines bladder volume. Identifies incomplete bladder emptying.

Blood urea nitrogen (BUN)

Laboratory test that determines amount of nitrogen in blood that comes from urea. Used as an indicator of kidney function.

Urinalysis

Urine screening test. Includes physical observation, chemical tests, and microscopic evaluation.

Voiding cystourethrography

X-ray of the bladder and urethra. Performed before, during, and after voiding using a contrast medium to enhance imaging.

cystoscopy

visual examination of the bladder

cystourethrography

process of recording (radiography) the bladder and urethra

pyelography

process of recording (radiography) the renal pelvis

pyeloplasty

surgical repair of the renal pelvis

urethrotomy

incision of the urethra

proteinuria

protein in urine

Catheterization

Insertion of a catheter into a body cavity or organ. Used to instill a substance or remove fluid. Most commonly performed through urethra into the bladder to withdraw urine.

Hemodialysis

Patient’s blood is diverted into a dialysis machine for filtering.

Peritoneal dialysis

Dialysis in which patient’s own peritoneum is used as the dialyzing membrane. Contaminated fluid drains out and is replaced with fresh solution.

Extracorporeal shock-wave lithotripsy (ESWL)

Powerful sound-wave vibrations break up calculi in urinary tract or gallbladder. Administration of an oral dissolution drug removes stones and their fragments during urination.

Renal transplantation

Diseased kidneys replaced by transplanted kidney.

Antibiotics

Drugs which treat bacterial infection of urinary tract. Act on the bacterial membrane or one of its metabolic processes. Type of antibiotic prescribed depends on the infecting organism and the type and extent of infection.

Antispasmodics

Drugs which suppress spasms in ureter, bladder, and urethra by relaxing smooth muscles lining their walls. Allow normal emptying of the bladder

Diuretics

Drugs which promote and increase excretion of urine.