US Department of Health and Human Services

Terms & Topics A-Z

The DONATE LIFE Glossary provides a listing of commonly used organ donation and transplantation terms.

A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

Allocation — The system of ensuring that organs and tissues are distributed fairly to patients who are in need.

Anti-Rejection Medicine (immunosuppressive drugs) — Medicines that reduce the body’s ability to reject a transplanted organ or tissue.

Antibody — A protein substance made by the body's immune system to attack a foreign substance, for example, a transplanted organ, blood transfusion, virus or pregnancy. Because antibodies attack transplanted organs, transplant patients must take powerful drugs. (See anti-rejection medicine.)

Antigen — A foreign substance, such as a transplanted organ or tissue, that triggers the body to reject it (destroy it.)

Blood Vessels — The arteries, veins, and capillaries through which blood circulates. Blood vessels can be donated and transplanted.

Bone — Dense tissue that forms the skeleton. Bone can be donated and transplanted.

Bone Marrow — A thick liquid substance found in the body's hollow bones, such as legs, arms and hips. Marrow consists of the stem cells that develop into blood cells (platelets, red blood cells, and white blood cells.) Marrow for transplant is usually collected from the pelvic bone.

Brain Death — Occurs when a person’s brain activity stops permanently. It is impossible to return to life after brain death.

Cadaveric donors — Also called, non-living donors, are those who donate their organs or tissue after they have been declared brain dead.

Cold Ischemia Time — The time an organ is without blood circulation—from the time the organ is removed from the donor to the time it is transplanted into the recipient.

Connective Tissue — Forms the supportive and connective structures of the body.

Cornea – In the eye this is the transparent outer covering of the iris and pupil. Corneas can be donated and transplanted to restore sight in those with damaged corneas.

Cross-Matching — A blood test performed before the transplant to find out if the transplanted organ will be rejected by the recipient. If the test is positive then the donor and recipient are “incompatible” and the transplant can not be done.

Cyclosporine — This medicine suppresses the body’s immune response thereby preventing organ rejection.

Deceased Donor — A person who has been declared dead and whose organs and/or tissue have been donated to a transplant recipient.

Donation — In relation to organ and tissue transplantation and blood transfusion, this is the act of giving organ(s), tissue, or blood, without compensation, to someone else.

End-stage Organ Disease — A disease that leads, ultimately, to functional failure of an organ. Some examples are emphysema (lungs), cardiomyopathy (heart), and polycystic kidney disease (kidneys).

End-stage renal disease (ESRD) — A very serious and life-threatening failure of the kidneys to remove waste (ultimately urine) from the body. This condition is related to high blood pressure and is treatable with dialysis, where the waste is removed by a machine. However, the preferred treatment of ESRD is kidney transplantation. Transplantation offers the patient "freedom" from dialysis so that the patient can lead a more normal lifestyle.

Genetic Disorder — A disease or disorder related to heredity, birth or origin.

Graft — A transplanted organ or tissue. Usually, a reference to transplanted skin, as in “skin graft.”

Heart — A muscular organ that pumps blood through the body. The heart can be donated and transplanted.

Heart valves — Prevent the back flow or leakage of blood as blood is being pumped through the chambers inside of the heart. The heart valves can be donated and transplanted.

Histocompatibility — Refers to the examination of antigens to determine if the donor organ will “match” and be compatible with the transplant recipient’s body. This routine test is often called tissue-typing and helps identify the most suitable recipient for a donated organ.

Idiopathic — Of, relating to, an organ being damaged or destroyed by a disease or condition of unknown origin.

Immune response — The body’s natural defense against foreign objects or organisms that invade the body, such as bacteria, viruses, or transplanted organs.

Immunosuppressive Drugs — Chemical agents that cause the human body not to produce antibodies that normally fight off foreign material in the body. The production of these antibodies needs to be suppressed in order to permit the acceptance of a donor organ by the recipient's body.

Informed Consent — The process of reaching an agreement based on a full disclosure and full understanding of what will take place. Informed consent has components of disclosure, comprehension, competence and voluntary response. Informed consent often refers to the process by which one makes decisions regarding medical procedures, including the decision to donate the organs of a loved one.

Intestines — The portion of the digestive track extending from the stomach to the anus, consisting of the stomach, the upper segment (small intestine) and lower segment (large intestine.) The intestines can be donated and transplanted.

Kidneys — A pair of organs that maintain proper water and electrolyte balance, regulate acid-base concentration, and filter the blood of metabolic waste, which is excreted as urine. Kidneys can be donated and transplanted.

Ligaments — Fibrous bands or sheets link two or more bones, cartilages, or structures together. Ligaments provide stability to a joint during rest and movement and protects against excessive movements such as hyper–extension or hyper–flexion. Ligaments can be transplanted.

Liver — A large reddish-brown organ that secretes bile and is active in the formation of certain blood proteins and in the metabolism of carbohydrates, fats, and proteins. The liver can be donated and transplanted.

Living Donor — A person (unrelated or related to the transplant recipient) who donates a kidney or part of a lung or liver while they are still alive.

Lungs — Air is inhaled into the lungs, and oxygen in the air is exchanged for carbon dioxide which is then exhaled. The exchange occurs in the blood as it circulates through the sponge-like lung tissue. The lungs can be donated and transplanted.

Match — The degree of compatibility, or likeness, between the donor and recipient.

Metabolic Disorder — A condition or disease related to dysfunction in the chemical processes and activities of the body (i.e. metabolism).

National Organ Transplant Act (NOTA) — Passed by Congress in 1984, NOTA initiated the development of a national system for organ sharing and a scientific registry to collect and report transplant data. It also outlawed the sale of human organs.

Organ — A part of the body, made up of various tissues, which perform a particular function. Transplantable organs are: heart, intestines, liver, lungs, kidneys, and pancreas.

Organ Preservation — Methods used to maintain the viability or organs between removal from the donor and transplantation into the recipient. These methods include preservation solutions, pumps, and cold storage. Preservation times can vary from 2 to 48 hours depending on the type of organ being preserved.

Organ Procurement Organizations (OPO) — the OPO staff (transplant coordinators) coordinate activities relating to organ donation in states and regional areas throughout the U.S. Their activities include: evaluating potential donors, discussing donation with family members, arranging for the donation process (removal and transport of donated organs,) and educating the public about the need for donors.

Pancreas — Long, irregularly shaped gland, which lies behind the stomach. Special glands in the pancreas secrete insulin. Pancreas transplants give the patients with diabetes a chance to become independent of insulin injections. In addition to insulin, the pancreas secretes digestive enzymes (into the small intestine) that aid in the digestion of proteins, carbohydrates, and fats.

Recipient — In the context of organ and tissue transplantation this is the patient receiving the donated organ or tissue.

Rejection (Acute and Chronic) — The body’s way of protecting itself against a foreign invader such as infectious germs. The body sees the transplanted organ or tissue as a foreign invader and attempts to destroy it. This can be acute and happen very quickly or chronic which would be the slow failure of an organ to function.

Scientific Registry of Transplant Recipients (SRTR) — In 1987, Congress passed the National Organ Transplant Act that mandated the establishment of the Organ Procurement and Transplantation Network and SRTR. The purpose of the SRTR is to provide ongoing research to evaluate information about donors, transplant candidates and recipients, as well as patient and graft survival rates. The SRTR contains historical data from October 1, 1987 to the present. The registry tracks all transplant patients from the time of transplant through hospital discharge, and then annually for up to 3 years or until graft failure or death. URREA, University Renal Research and Education Association, operates the SRTR under contract with the Federal Government.

Skin — This is the largest “organ” of the body and has several different functions (e.g. protection from infection, fluid balance, cooling). The top layers of skin tissue are often transplanted. Skin grafts can save the life a burn victim and can provide severely scarred patients with a better quality of life.

Tendon — A tough, flexible band of fibrous tissue that connects muscles to bones. The skeletal muscles move the bones for walking, jumping, lifting, etc. by contracting and pulling the bones. The tendon attaches to the muscle and bone and transmits the force of the muscle contraction to the bone. Tendons can be transplanted.

Tissue — An organization of similar cells that perform a special function. Examples of tissues that can be transplanted are bones, corneas, heart valves, ligaments, veins, and tendons.

Transplantation — The transfer of cells (e.g. stem cells), tissue, or organs from one person to another or from one area of the body to another.

Transplantation, Allogeneic (allograft) — Transplantation between genetically different members of the same species. Nearly all organ and bone marrow transplants are allografts. These may be between brothers and sisters, parents and children, or between donors and recipients who are not related to each other.

Transplantation, Autologous — Transplantation of an organism’s own cell or tissues. This type of transplantation can be used to repair or replace damaged tissue. For example, autologous bone marrow transplantation permits the use of strong cancer therapies that can damage bone marrow. Once the treatment is completed marrow that had been removed and not affected by the therapy is transplanted back into the patient.

Transplant recipient — A person who had received a tissue or organ transplant.

United Network for Organ Sharing (UNOS) — A nationwide umbrella for the transplant community; a non-profit organization that administers and maintains the Nation's organ transplant waiting list under contract with the Health Resources and Services Administration of the U.S. Department of Health and Human Services. Located in Richmond, Virginia, UNOS also brings together medical professionals, transplant recipients and donor families to develop organ transplantation policy.

Waiting List (sometimes called a “wait list”) — A national list that exists for all patients who are waiting for a transplant. It lists the total number of patients and the numbers of patients waiting for specific organs. It is used to locate the best recipient for a particular donated organ.