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
The King of Limbs Up the Ghost" is an acoustic guitar ballad with layered vocal harmonies. The final track, "Separator", has guitar and piano, a "brittle" drum loop, and echoing vocals. Yorke said he felt "The King of Limbs" was a "visual" album, with lyrics and artwork about "wildness" and "mutating" inspired by his environmental concerns. The album title is thought to refer to the King of Limbs, an ancient oak tree in Wiltshire's Savernake Forest, near Tottenham House, where Radiohead recorded "In Rainbows". At eight tracks and 37 minutes in length, "The King of Limbs" is Radiohead's shortest album. O'Brien explained that Radiohead