GCSE Biology 3

Card Set Information

Author:
Anonymous
ID:
214336
Filename:
GCSE Biology 3
Updated:
2013-04-18 18:20:38
Tags:
CGP
Folders:

Description:
Revision
Show Answers:

Home > Flashcards > Print Preview

The flashcards below were created by user Anonymous on FreezingBlue Flashcards. What would you like to do?


  1. where are the kidneys located in our bodies
  2. Show where nephrons are in the kidneys
  3. Show an enlarged view of a nephron
  4. Nephrons are
    Filtration units in the kidney
  5. What stages occur in the kidney
    • Ultrafiltration 
    • reabsorption 
    • release of waste
  6. Explain ultrafiltration
    • A highs pressure is built up which squeezes water , urea , ions and sugar out of the blood and into the bowman's capsule 
    • the membranes between the blood vessels and the bowman's capsule act like filters so big molecules like protein ands and red blood cells are not squeezed out . They stay in the blood
  7. Explain reabsorption
    • As the liquid flows along the nephron , useful substances are reabsorbed back into the blood : 
    • 1) all the sugar is reabsorbed this involves the process of active transport against the concentration gradient
    • 2) sufficient ions are reabsorbed . Excess ions are not . Active transport is needed 
    • 3) sufficient water is reabsorbed
  8. Explain release of wastes
    The remaining substances including urea continue out the he nephron , into the ureter and down the bladder as urine
  9. The kidneys remove
    • waste substances from the blood
    • 1) if the kidneys didn't work properly , waste substances build up In the blood and you lose your ability to control the levels of ions and water in your body . eventually this leads to death 
    • 2) people with kidney failure can be kept alive by having dialysis treatment - where the machines do the job of the kidneys . Or they have a kidney transplant
  10. Dialysis machines
    Filter the blood
  11. Using a diagram explain how a dialysis machine works
    • dialysis has to be done regularly to keep the concentrations of dissolved substances in the blood at normal levels , and toremove waste   substances  
    • in a dialysis machine the persons blood flows alongside a selectively permeable barrier , surrounded bY dialysis fluid . Its permeable to things like ions and waste substances , but not big molecules like protein (just like membranes in the kidney) 
    • the dialysis fluid has the same concentration of dissolved ions and glucose as healthy blood 
    • this means that useful dissolved ions and glucose Wont be lost from the blood during dialysis
    • only waste substances such as urea and excess ions and water diffuse across the Barrier
  12. Many patients with kidney failure have to have dialysis

What would you like to do?

Home > Flashcards > Print Preview