Memmler’s A&P
Chap 22
The Urinary System
The urinary system p464
• Excretion
• Systems active in excretion
– Urinary system
– Digestive system
– Respiratory system
– Integumentary system
Organs of urinary system p464
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•
•
•
Two kidneys
Two ureters
One urinary bladder
One urethra
Functions of the kidneys p464
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Excretion
Water balance
Acid-base balance
Blood pressure regulation
Regulation of red blood cell production
The kidney 465
• Located in
retroperitoneal space
• Divided into 2
regions:
– Renal medulla
– Renal cortex
• Nephrons: functional
unit of kidneys
The Nephron p466
• Glomerulus
• Convoluted tubule
• Peritubular
capillaries
• Blood pressure is
the force that
causes filtration.
Formation of urine p470
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•
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Glomerular filtration
Tubular reabsorption
Tubular secretion
Concentration of urine
Glomerular filtration p468
Formation of urine
p468
Renal control of blood pressure p471
• Renin: initiates the process that activates
angiotensin, a protein made by the liver that
elevates blood pressure.
• Angiotensin: promotes the release of
aldosterone and ADH and stimulates thirst,
raising blood pressure by increasing blood
volume.
p471-472
•Ureters
•Urinary bladder
•Urethra
Urine
• Normal constituents
– Nitrogenous waste
products (urea, creatinine)
– Electrolytes
– Pigment
Measure of dissolved
substances in urine is
called specific gravity
p473
• Abnormal constituents
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Glucose (glucosuria)
Albumin (proteinuria)
Blood (hematuria)
Ketones
WBCs (pyuria)
Casts (in larger numbers)
Disorders of urinary system p474
• Kidney stones (renal calculi) treated by lithotripsy
• Renal failure: chronic or acute
– Acute renal failure: fast onset
– Chronic renal failure: slow gradual loss of function
• Symptoms of chronic renal failure:
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Dehydration
Edema
Electrolyte imbalance
Hypertension
Anemia
Uremia
• Hemodialysis
• Peritoneal
dialysis
Dialysis p475
Disorders
• Cystitis
• Tumors
• Urinary incontinence
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Stress incontinence
Urge incontinence
Overflow incontinence
Enuresis
• Urethritis
• Cystoscopy
p477
Effects of aging
p479
• Kidneys lose some of their ability to concentrate
urine
• Decrease in number and size of nephrons
• Elderly people get more urinary tract infections than
young people: confusion
• Prostatic hypertrophy
• Decreased muscle tone in bladder and urinary
sphincters: urinary incontinence
Incontinence
Catheterization