Homeostasis: kidneys Flashcards
What is homeostasis?
controlling of internal conditions in the body
What needs to be controlled in the body?
- temperature
- glucose
- water and ions
- waste products
What happens if the ions and water are not balanced?
too much water may move in or out of cells and damage them
what does the kidney filter (ultra filtration)?
small molecules such as glucose, ions, amino acids, water
What is not filtered?
big molecules- proteins/ blood cells
What is reabsorbed?
ALL glucose
dissolved ions
water
By what method of exchange does selective reabsorption occur?
active transport
What is urea?
waste product from the breakdown of amino acids formed in liver
What are the components of urine?
- urea
- excess ions
- water
what two methods are used to treat people suffering with kidney failure?
- kidney dialysis
- healthy kidney transplant
What does the treatment of dialysis do?
restores concentration of dissolved substances in blood to normal levels and has to be carried out at regular intervals
What happens during dialysis?
- blood from artery passed through selectively permeable dialysis tube
- the dialysis tank contains same concentration of useful substances as blood so glucose and ion content kept the same
- constant flow of dialysis fluid removes urea from blood by maintaining concentration gradient
Adaptations of dialysis tubing/fluid
- tubing is coiled - maximum time for exchange
- fluid at body temprature so doesnt affect thermoregulatory system
What happens during a kidney transplant?
a diseased kidney is replaced with a healthy one from adonor
Problems with transplants
- organ rejection due to antigens on surface of organ causing body to respond by attacking with antibodies
