Keel (bird anatomy) Keel (bird anatomy) A keel or carina (plural carinae) in bird anatomy is an extension of the sternum (breastbone) which runs axially along the midline of the sternum and extends outward, perpendicular to the plane of the ribs. The keel provides an anchor to which a bird's wing muscles attach, thereby providing adequate leverage for flight. Keels do not exist on all birds; in particular, some flightless birds lack a keel structure. Historically, the presence or absence of a pronounced keel structure was used as a broad classification of birds into two orders: Carinatae (from "carina", "keel"), having a pronounced
Sociopolitical issues of anatomy in America in the 19th century set up to teach people the natural and moral sciences of the human body, anatomy museums gradually declined in status with the progress of medical science and education. In postbellum America, the division between high and low medicine increased. The focus of public scientific education turned toward the structures and functions of plants, animals, and cells, and this was done through politically and socially approved public school curriculums and sanitary fairs. These other avenues not only appeared more legitimate, but also reduced the uniqueness of anatomy museums. Anatomy museums' popularity also suffered with the establishment of nonprofit art and natural