Replacments in the body

A transplant is a type of operation that removes and replaces an object inside the body,

This could include organs such as the heart, kidney, liver and also other things like hip joints, knee joints or even the lens on your eyes.

There are two types of transplants,

Mechanical replacments

Biological replacments

A mechanical replacment is where an non-organic object is used to replace an object in your body

this can be objects such as artifical pacemakers or joints.

some mechanical replacments are used during a operation, such as the "heart and lung machine". This machine is used to keep the blood oxygenated while a operation is performed on the heart or lung.

these replacments have to meet certain targets if they are to be used :

- small to fit inside the body or to transport

- lightweight for same reasons as size

- battery powered to allow patient freedom

- strong materials to prevent breakages

- unreactive materials with any chemicals in the body

A biological replacement is an organic replacement. this means that the object is a living part of a human body.

Few things can be donated while a person is living, these things include: blood or bone marrow, also one kidney can be donated

However most things are donated after a person has died, death allows more important object to be taken such as livers, hearts, lungs etc.

to donate an organ or body part you must carry a donor card. however this does not provide 100% garentee that your body parts will be taken for donation.

If you are brain dead (this is where the brain fails and you are unable to breath) then both your organs and tissues can be taken for donation

If you die from cardio-respiratory failed (the heart fails to pump your blood around your body) then only your tissues can be taken for donation

A waiting list for a transplant is caused by

- shortage of donors

- tissues or blood do not match

- size and age do not match

But after a waiting list and the transplant the patient is not completely cured. Rejection can cause the donated object to fail.

Rejection is where the body's immune system detects the recently transplanted organ or tissue as a threat, this then causes the white blood cells to attack the transplanted organ or tissue. If this occurs the patient can either be operated again or take immuno-suppressive drugs which calms down the immune system.

To prevent issues such as these donors are carefully matched to the patient but due to somthing called human leucocyte antigens (HLA) the white blood cells named leucocyte will still attack the organ. Family members have very similar HLA's and so most times the best match comes from a family member