Supernumerary body part considered to have lost much or all of their original function through evolution. These body parts can be classed as additional to the required functioning of the body. In human anatomy the vermiform appendix is sometimes classed as a vestigial remnant. Prosthesis is an artificial extension that replaces a body part, and cybernetics is the study of computer technology in relation to organisms which can include replacement or additional body parts. Body integrity identity disorder (BIID) is a psychiatric disorder in which a person thinks that they have one or more additional limbs than they should, despite having two arms
Theology of the Body part of longstanding Church tradition — a tradition that was created in the context of scriptural teachings. The ability of the human body to express "truth" through the sexual union of married couples is acclaimed. The moral wrongness of using artificial means to manipulate such a significant aspect of the created body is explained. Dominion over outside forces, and also self-mastery through discipline, are integral human drives. However, the language expressed by bodies, in this context the language expressed during sexual intercourse, is so damaged by the use of artificial contraception that the conjugal act ""ceases to be an act