Important for homeostasis. Remove urea from blood. Remove excess water from blood or conserve water. Remove excess mineral ions from blood or conserve mineral ions. Filter blood and reabsorb everything needed, e.g. glucose, by selective reabsorption . Produce urine.
Nephritis Can be treated using antibiotics ( Cystitis is inflammation of the urinary bladder) Kidney stones can be smashed into smaller pieces using ultrasound. Then the pieces are passed out of the body in the urine.
Healthy kidneys produce erythropoietin , a hormone that controls how fast new red blood cells are made. People with kidney failure don’t make enough of this hormone. As a result, they become anaemic because they can’t produce enough red blood cells (red blood cells only last between 18 and 36 hours). Patients can take synthetically produced erythropoietin (EPO) to ensure enough red blood cells are made.
Mrs Abrey Lesson 17 and 18 kidney failure
Why are your kidneys so important?1. The kidney is important in keeping conditions in the body constant – what is this called?2. What substance is removed by the kidney?3. What is the name of the vessel that carries the blood to the kidney?4. What happens to the blood as soon as it enters the kidney?5. What is not filtered out into the kidney tubules?6. How much glucose is reabsorbed into the blood?7. How much water and mineral ions are reabsorbed into the blood?8. What is the name of the vessel that carries the blood away from the kidney?9. What is the final product called once it has passed through the kidney and out via the ureter?
Problems in the kidney• Nephritis - sometimes the kidneys become inflamed e.g. due to bacteria• Kidney stones - hard mineral deposits formed in the kidney. They can pass into the urine and larger ones may stick in the ureter.
Kidney failure• When both kidneys stop working, this is kidney failure.• It may be caused by kidney disease, injury, high blood pressure, poisoning or dehydration.• If a person’s kidneys don’t work, waste products (urea) build up in the bloodstream and the person will die without treatment – either dialysis or a transplant.
What is kidney dialysis?• Kidney failure means death, unless the function of the kidneys is replaced.• Dialysis replaces kidney function – filters and cleans blood.• Depends on diffusion along concentration gradients from blood to dialysis fluid. Kidney dialysis in action
What is a kidney transplant?• Failed kidneys replaced by single healthy kidney from donor.• Donor usually dead, but may be living.• To prevent rejection by the immune system: – The kidney is as close a tissue match as possible. – The recipient takes immunosuppressant drugs for life.
Which is best – dialysis or transplant?Dialysis: Transplant:• Machines usually • No special diet. available. • No sessions of dialysis.• No problems with • Relatively inexpensive, tissue matching. particularly after surgery.• Has to happen at least • Need donor, often not available. twice a • Need tissue match. week for life. • Have to take• Expensive immunosuppressant long-term. drugs for life.• Have to watch diet. • Surgery every ten years or so.
Overcoming lack of organ donors• Xenotransplantation• Stem cell research