What does the term "autologous" refer to in a medical context?

The term "autologous" in a medical context specifically refers to cells or tissues that are taken from the patient's own body. This concept is significant in fields such as transplantation, where using autologous cells can reduce the risk of rejection or complications associated with donor cells. For example, in procedures such as autologous stem cell transplants, stem cells are harvested from the patient, processed, and then reintroduced into the same individual, promoting more favorable outcomes.

The other options do not accurately represent the definition of autologous. Cells taken from a donor or a relative imply a different source, which could increase the risk of compatibility issues. Stem cells from an embryo fall under a category of cells that are not derived from the individual's own body. Overall, the correct association of "autologous" with the patient's own body is crucial for understanding its application in various medical procedures and therapies.