Kidney transplants A kidney transplant enables a diseased kidney to be replaced with a healthy one from a donor. However, the donor kidney may be rejected by the immune system: Antigens are proteins on the surface of cells. The antigens on the cells of the donated kidney may be different to the recipient’s antigens. White blood cells do not recognise them as part of the recipient’s body. They produce antibodies which attack the antigens on the donor organ. To prevent rejection of the transplanted kidney: A kidney with a tissue-type similar to that of the recipient is used. The recipient is treated with drugs that suppress the immune system. Advantages Disadvantages Dialysis No major surgery needed. Diet needs to be controlled No waiting lists it carefully. – prevents people dying. Restricts normal life it takes – about 8 hours, several times a week. Kidney transplant No need for dialysis. Major surgery has many risks. The recipient can lead a Possibility of rejection. relatively normal life. Immunosuppresant drugs need to Diet does not need to be be taken for life. controlled. Some religious groups do not agree with organ donation. Temperature control All enzymes work best at 37˚C The metabolism of releases heat which warms the animal’s body. Metabolism is most efficient If internal temperature is maintained when the external temperature changes, Thermoregulatory centre Body temperature is monitored and controlled by the thermoregulatory centre in the This centre has receptors sensitive to the temperature of flowing through the brain. Also temperature receptors in the skin send impulses to the centre giving information about skin temperature. Skin Skin contains sweat glands Skin has network of capillaries just under the surface If the core body temperature is too high: vessels supplying the skin capillaries dilate (get wider): More flows through the capillaries. More heat is lost from the skin. Sweat glands release more sweat: This the body as it evaporates.
Kidney transplants A kidney transplant enables a diseased kidney to be replaced with a healthy one from a donor. However, the donor kidney may be rejected by the immune system: Antigens are proteins on the surface of cells. The antigens on the cells of the donated kidney may be different to the recipient’s antigens. White blood cells do not recognise them as part of the recipient’s body. They produce antibodies which attack the antigens on the donor organ. To prevent rejection of the transplanted kidney: A kidney with a tissue-type similar to that of the recipient is used. The recipient is treated with drugs that suppress the immune system. Advantages Disadvantages Dialysis 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. Kidney transplant No need for dialysis. The recipient can lead a relatively normal life. Diet does not need to be controlled. Major surgery has many risks. Possibility of rejection. Immunosuppresant drugs need to be taken for life. Some religious groups do not agree with organ donation. Temperature control All enzymes work best at 37˚C The metabolism of releases heat which warms the animal’s body. Metabolism is most efficient If internal temperature is maintained when the external temperature changes, Thermoregulatory centre Body temperature is monitored and controlled by the thermoregulatory centre in the This centre has receptors sensitive to the temperature of flowing through the brain. Also temperature receptors in the skin send impulses to the centre giving information about skin temperature. Skin Skin contains sweat glands Skin has network of capillaries just under the surface If the core body temperature is too high: vessels supplying the skin capillaries dilate (get wider): More flows through the capillaries. More heat is lost from the skin. Sweat glands release more sweat: This the body as it evaporates.
new_unit_3_summary_notes.docx