Radius

The 'spindle bone (radius) is located on the lateral side of the forearm (radial direction). It is similar in shape to the ulna, but is narrower proximally than distally. Aiming for the thumb. We divide it into three parts:
 * caput radii - proximal part of cylindrical shape;
 * corpus radii – triangular body;
 * distal part - the distal end of the radius.

Caput radii

 * The head of the spindle bone has a barrel shape and is entirely covered by 'articular cartilage;
 * The proximal surface is articulated with the capitulum humeri;
 * the annular articular surface 'circumferentia radii fits into the notch on the ulna;
 * the head of the radius is connected to the ``corpus radii neck (collum radii'').

Corpus radii

 * The body of the spindle bone has three edges (margo anterior, posterior et interosseus);
 * the interosseous edge is connected to the edge of the same name on the ulna by a fibrous membrane "membrana interossea antebrachii";
 * on the body there is a roughness (tuberositas radii') where the m. biceps brachii is attached;
 * The foramen nutricium is located about halfway up the bone and is directed proximally.

Distal part of radius

 * It is a wider area (facies articularis carpalis radii) covered by articular cartilage, which participates in radiocarpal articulation;
 * the distal part of the "ulna" fits into the small notch here;
 * the distal part of the radius 'rotates around the axis formed by the ulna during pronation and supination.

Related Articles

 * Upper Extremity Bones
 * Muscles of the upper limb