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
History of anatomy their valves, and tracing the course of the blood from the right to the left side of the heart. The rise in anatomy lead to various discoveries and findings. In 1628, English physician William Harvey observed circulating blood through dissections of his father’s and sister’s bodies. He published "De moto cordis et sanguinis", a treatise in which he explained his theory. In addition, during the 17th century, Galileo Galilei introduced the experimental method to scientific research. This led to innovation and change in anatomy. In Tuscany and Florence, Marcello Malpighi founded microscopic anatomy, and Nils Steensen studied the anatomy of