Kidney Dialysis and Transplants

• Objectives:*Describe the process of dialysis and explain

how it controls the concentration of glucose, urea and protein in the blood

**Describe the working of a kidney dialysis machine

***Describe the advantages and disadvantages of kidney transplant compared with dialysis

The three ways homeostasis is maintained are Thermoregulation by …….Osmoregulation by……..Blood glucose regulation by ……

The working kidney

• Filters 150L of blood per day

• Entire blood within the body filtered once every 45 minutes

• Produces 1.5 – 2 L urine per day

Problems with the kidneysKidney stones

High salt and minerals in your diet can lead to stones precipitating out

Extremely painful Have to be excreted from the body in the urine

Renal damage / failure The kidney is no longer able to filter the blood

effectively▪ Plasma not properly reabsorbed▪ Proteins and cells pass through bowman’s capsule▪ Presence of protein in urine is a sign of kidney failure

Living without kidneys

• A person can survive with only 1 kidney• However, no working kidneys death• How do we know kidney is not working?

• Options:– Dialysis– Transplantation

Dialysis machine

Dialysis•The blood vessels in the arm are connected to a dialysis machine.•In the dialysis machine a person’s blood flows between partially permeable membranes.•The dialysis fluid contains the same concentration of useful substances as the blood.•This ensures that glucose and useful mineral ions are not lost. •There is a high concentration of urea in the person’s blood, and no urea in the dialysis fluid.•There is a concentration gradient of urea between the blood and the dialysis fluid.•Urea passes out from the blood into the dialysis fluid by diffusion. •Treatment by dialysis restores the concentrations of dissolved substances in the blood to normal levels.•It has to be carried out at regular intervals.

Transplantation

• Organ removed from either dead person or living person if not an essential organ

• Inserted and connected to patient

• Damaged organs sometimes removed

• Donor organs not always connected into position of old organ

Transplantation

Advantages / disadvantages

Advantages DisadvantagesDialysis • No major surgery needed.

• No waiting lists – it prevents people dying.

• Diet needs to be controlled carefully.

• Restricts normal life – it takes about 8 hours, several times a week.

• Dialysis cannot replace all the functions of a kidney

Kidney transplant • No need for dialysis.• Transplant can replace all

the functions of a kidney• The recipient can lead a

relatively normal life.• Diet does not need to be

controlled.

• Major surgery has many risks.Difficulty of finding suitable donor as donor’s and recipient’s blood and tissue types need matching

• Possibility of tissue rejection.• Immunosuppresant drugs need to

be taken for life. This means they are prone to certain infections and suffer longer from those infections.

• Patient need bone marrow radiation to stop white blood cell production

• The donated kidney only lasts for about 9 years.

• Some religious groups do not agree with organ donation.