Urinary System

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Urinary System

• Can you hold it long enough for me to get through
  this lecture?

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QUICK REVIEW OF ELIMINATION

• Lungs eliminate CO2
• Sweat glands eliminate excess heat, salt
• Digestive tract- indigestible solids, bacteria
• Urinary tract is the main system of elimination

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A little vocab

• Uria or Ur- urine
• Cyst- bladder
• Nephr or Ren- kidney
• Dys- painful

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• Anuria
• Without urine
• Cystitis
• Inflammation of the bladder
• Dysuria
• Painful urination
• Hematuria
• Blood I urine
• Hydronephrosis
• gt water in kidney
• Renal
• Pertaining to kidney

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The Urinary Tract

• Urinary tract consists of 2 kidneys, 2 ureters,
  one bladder and one urethra.
• Kidney location
• Retroperitoneal
• Dorsal wall of abdominal cavity
• 12th thoracic and 3rd lumbar vertebrae
• Urethra
• 1.5 inches in women, 8 inches in men

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• Outer layer- Cortex
• Inner layer- Medulla
• Calyx- collects urine as it is formed, join
  together to form the ureter

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• Kidneys filter blood- 2, 000 L/day (500 gal)
• remove waste products and reabsorb water, other
  valuable substances.
• 1.5 L of urine/day
• Metabolism produces toxic substances- esp
  nitrogen containing waste as a by-product of
  protein breakdown
• We eliminate nitrogen as urea- water soluble

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• The main functional unit of the kidney is called
  the NEPHRON.
• 1 million per kidney
• Most of nephron located in renal cortex
• Loop of Henle is located in the renal medulla

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• Capillaries in glomerulus filter blood- Bowman
  capsule collects ultra filtrate
• Through passive and active diffusion, 95 of
  water is reabsorbed, along with K, Na, Ca
• Other things are actively excreted, like drugs.
• Excretion is controlled by hormones such as ADH
  from hypothalamus

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• Urine is made in 4 steps
• Filtration
• Reabsorption
• Secretion
• Excretion
• A urinalysis is the most common non-invasive
  medical test
• ordered

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Diseases of the Kidney

• Acute Kidney failure- sudden loss of function
• Causes nephritis, shock, injury, heart failure
  or poisoning
• Symptoms anuria or oliguria. Uremia, nausea,
  coma, death
• Chronic Kidney failure- gradual loss of function
  due to hypertension (high blood pressure) or
  endocrine disease
• Cystitis- inflammation of the urinary bladder

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Dialysis, Kidney transplant

• Hemodialysis- serves as an artificial kidney
  2-3x/week for 2-4 hours
• Peritoneal dialysis- uses patients own
  peritoneal lining to filter blood
• Kidney transplant- need suitable donor. Only need
  one, but must take anti-rejection drugs for the
  life of the patient