Homeostasis and Response - The Kidneys and Dialysis Flashcards
The main job of the kidneys is to…
filter the blood to get rid of waste.
What is the primary waste that the kidneys are removing?
UREA
Where is urea made?
The liver during deamination.
Explain deamination:
If the body has more amino acids than it needs, it can convert them into lipids or carbs, which can be stored as an energy source for later.
What is the downside of deamination?
It produces urea as a waste product which has to be excreted by the kidney.
What useful things do the kidneys regulate?
ions - we need sodium and potassium, which we get from food, but if the levels of these get too low or high, this can cause damage to our cells -> lose ions through sweating but this is not enough.
water levels
Describe the process of filtration:
The kidneys have millions of structures called nephrons.
Nephrons have tubules.
As blood passes through the kidneys, the tubules absorb small molecules such as glucose, urea amino acids and water.
Large molecules such as cells or proteins are not absorbed.
What happens after filtration?
selective re-absorbtion
Describe the process of selective re-absorbtion:
- As the substances continue moving through the tubules, useful substances are re-absorbed. This includes ALL GLUCOSE, because glucose is always useful. Some water, getting rid of excess. NO UREA.
How are water levels regulated in the body?
The hypothalumus located in the brain detects the conc. of water in the bloodstream.
WHAT IS ADH?
- ADH is released by the pituitary gland.
- ADH causes more water to be released and concentrated urine to be formed.
- When dehydrated, more ADH is released and concentrated urine is produced (more water is absorbed in selective re-absorbtion).
- When overhydrated, less ADH is released and dillute urine is prouduced (more water is lost during filtration and selective re-absorbtion).
EXAMPLE OF NEGATIVE FEEDBACK)
It basically stimulates the kidneys.
If the kidneys cannot remove urea and excess water or salts from the blood, and the patient is still waiting for a transplant, the patient is…
connected to a kidney dialysis machine.
_______ ___________ are taken by the patient during dialysis to prevent the blood from clotting in the process.
blood thinners.
Dialysis fluid in the dialysis machine contains…
OPTIMUM LEVELS of salts, water and glucose, and no urea. This is to replicate optimum levels that the patient needs in the blood. Whether or not the blood of the patient gains or loses water and salt depends on the person. If they have optimum or too little water in their blood, they will stay the same or absorb some from the dialysis fluid. If they have excess, some will move down the concentration gradient into the dialysis fluid.
Dialysis machines use a man-made _____ ________ ______________
partially permeable membrane
ADVANTAGES OF DIALYSIS:
- maintains health
- no risk of surgery
- no risk of rejection
- does not require medication daily
DISADVANTAGES OF DIALYSIS:
- requires expensive equipment
- risk of infection
- risk of blood clotting
- time consuming
- restricted diet and weight loss
- temporary treatment so will eventually need surgery.
Dialysis fluid is constantly replaced because the levels of salt water and glucose will eventually…
reach equilibrium, and nothing will diffuse across anymore. To retain the concentration gradient, the fluid is constantly changed.
Blood enters the kidneys via the
renal artery
Blood leaves the kidneys via the
renal veins
The ____ carries urine from bladder out of body
urethra
