rib (redirected from ribbing)

rib, one of the slender, elongated, curved bones that compose the chest cage in higher vertebrates. Ribs occur in pairs, and are found in most vertebrates; however, in some lower vertebrates, including fishes, they run along the entire length of the backbone. The ribs of the snake are used in locomotion. In the human there are 12 pairs of ribs. Each rib is connected to the vertebral column by strong ligaments. In the front, a flexible section of cartilage connects the rib to the sternum, or breastbone. Below the 7th rib, the 8th, 9th, and 10th ribs are not attached directly to the sternum, but to the cartilage of the 7th rib. The 11th and 12th pairs of ribs are not attached in front at all, and hence are known as floating ribs. Technically, these ribs do not "float," however, but are attached to the vertebral column in the rear and extend only part of the way around the chest. In birds and mammals, ribs enclose the lungs and heart and assist in the process of breathing. During inhalation the ribs move upward and farther apart, expanding the chest cavity. During exhalation their downward motion aids in expelling air from the lungs. See skeleton.

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rib

1. any of the 24 curved elastic arches of bone that together form the chest wall in humans. All are attached behind to the thoracic part of the spinal column

2. the corresponding bone in other vertebrates

3. a structural member in a wing that extends from the leading edge to the trailing edge and maintains the shape of the wing surface

4. a projecting moulding or band on the underside of a vault or ceiling, which may be structural or ornamental

5. any of the transverse stiffening timbers or joists forming the frame of a ship's hull

6. any of the larger veins of a leaf

7. a projecting ridge of a mountain; spur