Homeostasis Flashcards
How is carbon dioxide removed?
By the lungs
What waste products must the body remove?
Carbon dioxide
Urea
How is urea produced?
By the liver when it breaks down amino acids
What internal conditions must be carefully monitored?
Temperature
Water content
Ion content
Blood sugar
How is water lost?
By breathing
Sweating
Excess in urine
How is ion content reduced?
By the kidneys in urine
What is the danger of too much water or ion content?
Too much water may move in and out of cells which could damage them
What system are the kidneys part of?
Urinary
What are the functions of the kidneys?
Clean the blood by removing urea
Maintain concentration of dissolved substances (sugar, ions)
Maintain water level
How is urine produced?
Blood is filtered. Water, ions, urea and sugar pass into kidney tubules
SELECTIVE REABSORPTION absorbs useful substances (ions and sugars which may have to use active transports)
Urea, excess ions and water stay in tubules
Pass into bladder
How can kidney failure be treated?
Dialysis
Kidney transplant
How does a dialysis machine work?
Blood is separated by partially permeable membrane in machine
Membrane allows urea and excess substances to pass to the dialysis fluid
How do dialysis machines ensure that glucose and ions are not lost?
Have same concentration gradients as useful substances in blood
What precautions must be taken to reduce risk of kidney rejection?
Tissue type must be as close as possible
Immunosuppressants
Why might the body reject a kidney after transplant?
Antibodies may attack them because they don’t recognise them