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
Gray's Anatomy is playing with his train sets. The 1996 Steven Soderbergh film "Gray's Anatomy", featuring monologuist Spalding Gray, also takes its name from the title of the book, as does "Gray's Anatomy: Selected Writings", a 2009 book by British political philosopher John N. Gray. In the 1998 "" episode "", the new Emergency Medical Hologram designed by Ensign Kim begins reciting the contents of "Gray's Anatomy" when activated, beginning with a description of the cell. The American medical drama "Grey's Anatomy" (2005 –) takes its name from the textbook. The name of Jim Leonard Jr.'s 2006 play "Anatomy of Gray", which