12The renal artery- brings blood containing urea and other substances. The renal vein carries blood away from the kidneys after urea and other substances have been removed from the blood.Kidneys
13The structure of the kidney The structure of the kidney. Blood flows in through the renal artery, is filtered and leaves the kidney in the renal vein. The waste urine, containing water, salts, and urea, passes down the ureter to the bladder.
15Kidneys If you eat a lot of processed foods they are high in salt. The kidneys will remove excess mineral ions that can be lost in urine.
16How do your Kidneys work? Your kidneys filter your blood and then reabsorb everything you need.Glucose, amino acids, mineral salts and urea all move out of the blood into the kidneys by diffusion.
17How do your Kidneys work? Blood cells can not pass through the membrane as they are too big.
18How do your Kidneys work? Then, all of the sugar is reabsorbed back into the blood by active transport.The amount of water and mineral ions reabsorbed varies depending on what your body needs.This is called selective reabsorption.
19Higher TierBoth sugar and mineral ions move back into the blood by active transport.This is to make sure no sugar is left in the urine and the correct amount of mineral ions are reabsorbed.
20How do your Kidneys work The amount of water reabsorbed depends on what your body needs by a feedback mechanism.Urea is lost in your urine.However, some of it moves from the kidneys back into the blood by diffusion.
21How do your Kidneys work Kidneys have a rich blood supply so they constantly produce urine.It moves down the bladder until you wish to empty it.
23Learning Objectives To understand why kidneys fail. To know what dialysis is.To know how dialysis works.
24Dialysis- an artificial kidney Kidneys can be damaged in a number of ways;By infectionsGenetic problemsAccidents
25For centuries if someone had kidney failure it would lead to death. Nick Cannon had mild kidney failureFor centuries if someone had kidney failure it would lead to death.We can survive on one kidney very well, but total kidney failure would be fatal if not treated.But now there two methods to treat this, kidney dialysis or a kidney transplant.Liam has one kidney
26Dialysis- an artificial kidney If the kidneys have been damaged, toxins such as urea could build up.And salt and water balance can be lost.
27With dialysis the blood leaves their body and flow between a partially permeable membrane. On the other side of the membrane is dialysis fluid.
28Dialysis- an artificial kidney 3. The dialysis fluid contains the same concentration of glucose and mineral ions as normal blood plasma so there is no net movement of glucose out of the blood.4. It contains normal plasma levels of mineral ions so excess ions are lost from the blood.
29Dialysis- an artificial kidney 5. The dialysis fluid contains no urea, so all of the urea moves from the blood in to the dialysis fluid.
38Disadvantages of Dialysis Have to follow a carefully controlled diet (amount of water)Have to have long sessions connected to a dialysis machine.Many years of dialysis means it can become difficult to control the balance of substances.
39Advantage of DialysisIt is about life rather than death.
40Kidney machines can keep patients alive until a transplant becomes available but they have several disadvantages:they are expensivethe patient must have his or her blood connected to the machine for several hours every weekpatients must follow a very rigid diet to avoid complicationsthey only work for a limited time for a patient
44Kidney TransplantsIf kidneys fail they can be replaced by a healthy kidney from a donor.
45Problems with Kidney Transplants Because the kidney comes from a different person, they will have different antigens on the surface.This means there is a possibility the kidney could be rejected by the immune system.
46Reducing the risk of rejection The tissue type is similar between the donor and the recipient and same blood group.Also the recipient will be given immunosuppresant drugs for the rest of their lives.
47Immunosuppresant drugs the down sides People who take these drugs means they can not deal with infectious diseases very well.
48Dialysis vs Transplants Advantages -Once a person has had a transplant they can eat what they like.They do not have to spend long periods of time having dialysis.Disadvantages -There is a risk of rejection.Have to take immunosuppresant drugs for the rest of their lives.Regular check up to ensure kidney is not being rejected.Finding a donor as there is a lack of donors avaliable.