Adapted from the glossary at, available online at


Allocation—A system of rules and guidelines used to determine how organs are distributed among the patients in need of an organ transplant. These policies and guidelines make sure that organs are distributed in a fair, ethical and medically sound manner.

Allograft—Describes when a transplant of an organ or tissue is between two people of the same species, for example from one human being to another.


Blood Vessels—is a term that refers to the arteries, veins, and capillaries that blood flows through in the body. Blood vessels can be donated and transplanted.

Bone—is dense tissue that forms the skeleton and supports the body. Bone can be donated and transplanted.

Brain Death—is a term that means the person’s death is due to their brain shutting down and becoming permanently non-functional. A person that is declared brain dead is not awake and cannot be woken up. They are not aware of anything around them, no longer breathes on their own and have no purposeful movement.


Circulatory Death— is when a person’s death is due to their heart stopping. There are many causes of cardiac or circulatory death. Just like brain death, there is no recovery from circulatory death.

Connective Tissue—are the parts of the body that form the supportive and connective tissues of the body, such as tendons, ligaments, cartilage and bone. Connective tissue surrounds many organs.

Cornea—is the transparent outer covering of the eye’s iris, colored part, and pupil. Corneas can be donated and transplanted to give people back their sight.


Deceased Donor—is a person who has been declared dead and whose organs and/or tissues have been donated for transplantation.

Donation—is the act of giving organ(s), tissue(s), or blood to someone else. It is illegal in the US to be paid or to receive something of value in exchange for the donation of an organ or tissue.

Dialysis—is a process used to remove excess fluid and toxic substances from the blood when the kidneys are not working right and unable to do so. See hemodialysis and peritoneal dialysis.

Donor Designation—is documentation that a person has decided to donate their organs, eyes, and/or tissues after death. This is usually found on a driver’s license or non-driver’s identification card or through enrollment in a donor registry.

Donor Registry—is a confidential electronic database in which people enroll and document their wish to be an organ and tissue donor. Most registries are for a single state, but a few serve more than one state.

People can enroll in most donor registries in a number of ways. Enrollment in most state donor registries is through the motor vehicle department offices. Many also have ways to join the registry online.


End-Stage Organ Disease—a term that refers to advanced disease that is permanent and results in the failure of an organ to function the way it should. Examples are emphysema (lungs), cardiomyopathy (heart), and polycystic kidney disease (kidneys).

End-Stage Renal Disease (ESRD)—is the complete or almost complete failure of the kidneys to function. The kidneys no longer remove wastes, toxins, fluid or other substances from the body like they would if they were working properly.


Graft—is a transplanted organ or tissue.


Heart—is a muscular organ located in the human chest that pumps blood through the body. The heart can be donated and transplanted.

Heart Valves—Are the parts of the heart that prevent the back flow or leakage of blood as it is being pumped and flows through the heart. Heart valves can be donated and transplanted.


Intestines—include the different parts of the digestive tract starting below the stomach including the upper segment (small intestine) and lower segment (large intestine.) The intestines can be donated and transplanted.


Kidneys—Are a pair of organs that work to filter wastes and maintain the proper amount of water and other substances in the body. Kidneys can be donated for transplantation by deceased and living donors.


Ligaments—are fibrous tissues that link bones, cartilages, and other structures together. Ligaments provide stability and protection to and around joints throughout the body. Ligaments can be transplanted. See Connective Tissue.

Liver—is a large reddish-brown organ that makes substances that your body needs to process the foods you eat and forms certain blood proteins. The liver, like the kidneys, also helps remove wastes and toxins from the blood. The liver can be donated by deceased donors, and a section or part of a liver (lobe) can be donated by a living person for transplantation to a person in need. The liver of both the living donor and the part transplanted into the recipient will grow to full size with time.

Living Donor—is a person who donates an organ or tissue to another person while they are still alive.

Lungs—are organs that enable breathing to take place, providing life-sustaining oxygen to the body and its organs. The lungs of a person that has died can be donated and transplanted, and a portion of a lung, a lobe, can be donated by a living donor.


Marrow—is a thick liquid substance found in the body’s hollow bones, such as the leg, arm and hip bones. Marrow consists of specific cells that make different types of blood cells (platelets, red blood cells, and white blood cells). Marrow for transplant is usually collected from the pelvic bone.

Match—is a term used to describe the degree of similarity or likeness in very specific ways, such as blood type, between a donor and a recipient.


National Organ Transplant Act (NOTA)—is a law passed by Congress in 1984. NOTA started the development of a national system of organ sharing and the collection of transplant data for analysis and quality improvement. This law also outlawed the sale of human organs in the United States.


Organ—is a part of the body which performs a particular function. Transplantable organs are: heart, intestines, liver, lungs, kidneys, and pancreas.

Organ Donation—is the giving an organ or a part of an organ for the purpose of transplantation into another person or research. Organ donation can involve a donor that has died, who can give kidneys, pancreas, liver, lungs, heart, intestinal organs, or a living donor, who can give a kidney or a portion of the liver, lung, or intestine.

Organ Preservation—are methods used to maintain the “health” of organs between removal from the donor and transplantation into the recipient. These methods include use of preservation solutions, pumps, and cold storage. Organs differ in how long they can be preserved. Preservation times can vary from 2 to 48 hours depending on the type of organ.

Organ Procurement Organizations (OPO)—are organizations located throughout the U.S. designated by the Centers for Medicare and Medicaid Services (CMS) that are responsible for managing the organ donation process, including the surgical recovery of donated organs, and promoting organ and tissue donation in their service areas. OPOs evaluate potential donors, discuss donation with family members, and arrange for the removal and transport of donated organs. To increase donor registration, OPOs perform community outreach events to encourage people to sign up in their state donor registry. Find your local OPO and Eye and Tissue Bank


Pancreas—is a long, irregularly shaped gland that lies behind the stomach. Certain cells in the pancreas make and secrete insulin. Pancreas transplants give patients with diabetes a chance to live without insulin injections. Other pancreatic cells make substances that helps in the digestion of food.

Procurement, also referred to as Recovery—is the process of surgically removing the organ(s), eyes, cornea(s) or other tissue(s) from a donor for transplantation. See Recovery.


Recipient—In the context of transplantation, the recipient is the patient receiving the donated organ or tissue.

Rejection (Acute and Chronic)—is a process the body uses to protect itself against “foreign invaders”, that in most cases are germs that cause infections. In the case of a person who has received a transplanted organ, the body thinks the new organ is a foreign invader and attempts to destroy it (just like it would do with any germs that invaded your body). Acute rejection of a transplanted organ happens very quickly; chronic rejection is a slow process resulting in the failure of a donated organ to function.


Skin—Covers the outside of the entire body and is the largest organ of the body. Skin has several different functions including protecting the inner body from infection, helping maintain the bodies fluid balance and cooling. Skin grafts can save the life a burn victim and can provide severely scarred individuals with a better quality of life.


Tendons—Are tough, flexible bands of fibrous tissue that connects muscles to bones. Tendons help with walking, jumping, lifting, etc. Tendons can be transplanted. See Connective Tissue.

Tissue—is a body part consisting 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—is the placement of cells (e.g. stem cells), tissue, or organs removed from one person into another.

Transplant Recipient—is a person who has received a tissue or organ transplant.


Vascularized Composite Allograft (VCA)—is transplanted tissue of several different kinds such as skin, bone, muscles, blood vessels, nerves, and connective tissue. Examples of VCAs include: hand(s), arm(s), or face transplants. “Vascularized” means that the transplanted tissue, aka graft, require the surgical connection of blood vessels.


Waiting List—is a national database of all patients waiting for an organ transplant. It is generally broken up into “sub-lists” of patients waiting for different types of organs, e.g. kidney, liver, heart, etc.