Search results
Results from the WOW.Com Content Network
The head of the radius has a cylindrical form, and on its upper surface is a shallow cup or fovea for articulation with the capitulum of the humerus.The circumference of the head is smooth; it is broad medially where it articulates with the radial notch of the ulna, narrow in the rest of its extent, which is embraced by the annular ligament.
The ulna is longer than the radius, but the radius is thicker. The radius is a long bone, prism-shaped and slightly curved longitudinally. The radius is part of two joints: the elbow and the wrist. At the elbow, it joins with the capitulum of the humerus, and in a separate region, with the ulna at the radial notch. At the wrist, the radius ...
The ulna or ulnar bone (pl.: ulnae or ulnas) [3] is a long bone in the forearm stretching from the elbow to the wrist. It is on the same side of the forearm as the little finger, running parallel to the radius, the forearm's other long bone. Longer and thinner than the radius, the ulna is considered to be the smaller long bone of the lower arm.
The distal radioulnar articulation [1] (also known as the distal radioulnar joint, [2] or inferior radioulnar joint [1] [3]) is a synovial pivot joint between the two bones in the forearm; the radius and ulna. It is one of two joints between the radius and ulna, the other being the proximal radioulnar articulation.
The articular surface for the ulna is called the ulnar notch (sigmoid cavity) of the radius; it is in the distal radius, and is narrow, concave, smooth, and articulates with the head of the ulna forming the distal radioulnar joint.
The annular ligament binds the head of the radius to the radial notch of the ulna, preventing any separation of the two bones laterally.Therefore, the humeroradial joint is not functionally a ball and socket joint, although the joint surface in itself allows movement in all directions.
Beneath the neck of the radius, on the medial side, is an eminence, the radial tuberosity; its surface is divided into: . a posterior, rough portion, for the insertion of the tendon of the biceps brachii.
The radial notch of the ulna (lesser sigmoid cavity) is a narrow, oblong, articular depression on the lateral side of the coronoid process; it receives the circumferential articular surface of the head of the radius. It is concave from before backward, and its prominent extremities serve for the attachment of the annular ligament.