Main organs of excretory system by AmnaKhan

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									Excretory System

      Ewww!
   Giggle, giggle
                  Excretion
•   Digestive System     •   H2O, undigested food
•   Respiratory System   •   H2O, CO2
•   Skin                 •   H2O, salts
•   Urinary System       •   H2O, salts, poisons



                         • Why do we need to
                           drink lots of water?
           Regulating Fluids
•   Hypothalamus – in mid-brain
•   Detects fluid levels in blood
•   Sends hormone into bloodstream
•   Kidneys respond by increasing/decreasing
    urine output.
                  Kidneys
•   Main organs of excretory system
•   Bean-shaped
•   Red – because of blood supply
•   Back of abdomen near waist
•   Filter all blood every 5 minutes
Human Kidney
             Filtration – Step 1
•    Blood from renal (kidney) artery →
•    Capillaries (all wadded up) →
•    Nephron – cup and tube (duct)
    – Water, sugar, salt, waste → cup
    – Red cells, proteins left in capillary
    – Liquid → tubule
         Filtration – Step 2
• Most sugar, salt, H2O reabsorbed from
  tubules to capillaries
• → renal vein
• →main circulatory system
                   Urine
• Left behind in tubules
• Excess water, wastes
• Urea
  – excess amino acids
  – NH3+ CO2
• Average 1 liter/day
                  Liver
• Broken-down blood cells – bile
• Digestive fluid
                     Diseases
• Imbalances
   – Fluids
   – Salts
• Blockages
   – Kidney stones
   – Ultrasound blasts
• Infections - Nephritis
• Urine tests
   – for glucose (diabetes)
   – protein (heart disease)
                    Dialysis
•   Kidney failure – excess fluid
•   Patients can’t urinate
•   Artificial kidney filters blood
•   2-3 times weekly
•   2-4 hours at a time
             Transplant
• Kidney failure
• Live or dead donor
• Blood matches needed
  Preventing Kidney Diseases
• Diet
• Exercise
• Blood Pressure
          The Rest of the Story
•   Tubules
•   Ureters
•   Bladder (up to ½ liter)
•   Urethra
•   Sphincter muscle

								
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