Bone: Body of ulna
Bones of left forearm. Anterior aspect.
Latin	corpus ulnae
Gray's	subject #52 215
Dorlands/Elsevier	c_56/12260869

The body of the ulna at its upper part is prismatic in form, and curved so as to be convex behind and lateralward; its central part is straight; its lower part is rounded, smooth, and bent a little lateralward. It tapers gradually from above downward, and has three borders and three surfaces. Image File history File links Download high resolution version (700x1245, 71 KB) File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ... Latin is an ancient Indo-European language originally spoken in Latium, the region immediately surrounding Rome. ... Elseviers logo. ... The ulna (Elbow Bone) [Figs. ...

Borders

The volar border (margo volaris; anterior border) begins above at the prominent medial angle of the coronoid process, and ends below in front of the styloid process. Its upper part, well-defined, and its middle portion, smooth and rounded, give origin to the flexor digitorum profundus; its lower fourth serves for the origin of the pronator quadratus. This border separates the volar from the medial surface. The flexor digitorum profundis is a muscle in the forearm that flexes the fingers. ... Pronator quadratus is a square shaped muscle on the distal forearm that acts to pronate (turn so the palm faces downwards) the hand. ...

The dorsal border (margo dorsalis; posterior border) begins above at the apex of the triangular subcutaneous surface at the back part of the olecranon, and ends below at the back of the styloid process; it is well-marked in the upper three-fourths, and gives attachment to an aponeurosis which affords a common origin to the flexor carpi ulnaris, the extensor carpi ulnaris, and the flexor digitorum profundus; its lower fourth is smooth and rounded. This border separates the medial from the dorsal surface. In anatomy, flexor carpi ulnaris muscle is a muscle of the human forearm that acts to flex and adduct the hand. ... Extensor carpi ulnaris is a muscle, located in the forearm of humans that acts to extend and adduct the wrist. ... The flexor digitorum profundis is a muscle in the forearm that flexes the fingers. ...

The interosseous crest (crista interossea; external or interosseous border) begins above by the union of two lines, which converge from the extremities of the radial notch and enclose between them a triangular space for the origin of part of the Supinator; it ends below at the head of the ulna. Its upper part is sharp, its lower fourth smooth and rounded. This crest gives attachment to the interosseous membrane, and separates the volar from the dorsal surface. The Supinator muscle is a muscle of the human body. ... The Interosseous membrane is a broad and thin plane of fibrous tissue that separates many of the bones of the body. ...

Surfaces

The volar surface (facies volaris; anterior surface), much broader above than below, is concave in its upper three-fourths, and gives origin to the flexor digitorum profundus; its lower fourth, also concave, is covered by the pronator quadratus. The lower fourth is separated from the remaining portion by a ridge, directed obliquely downward and medialward, which marks the extent of origin of the pronator quadratus. At the junction of the upper with the middle third of the bone is the nutrient canal, directed obliquely upward. The flexor digitorum profundis is a muscle in the forearm that flexes the fingers. ... Pronator quadratus is a square shaped muscle on the distal forearm that acts to pronate (turn so the palm faces downwards) the hand. ...

The dorsal surface (facies dorsalis; posterior surface) directed backward and lateralward, is broad and concave above; convex and somewhat narrower in the middle; narrow, smooth, and rounded below. On its upper part is an oblique ridge, which runs from the dorsal end of the radial notch, downward to the dorsal border; the triangular surface above this ridge receives the insertion of the Anconæus, while the upper part of the ridge affords attachment to the supinator. Below this the surface is subdivided by a longitudinal ridge, sometimes called the perpendicular line, into two parts: the medial part is smooth, and covered by the extensor carpi ulnaris; the lateral portion, wider and rougher, gives origin from above downward to the Supinator, the abductor pollicis longus, the extensor pollicis longus, and the extensor indicis proprius. The Supinator muscle is a muscle of the human body. ... Extensor carpi ulnaris is a muscle, located in the forearm of humans that acts to extend and adduct the wrist. ... The Abductor pollicis longus muscle is a muscle of the human body. ... The Extensor pollicis longus muscle is a muscle of the human body. ... The Extensor indicis proprius (Extensor indicis) is a narrow, elongated muscle, placed medial to, and parallel with, the extensor pollicis longus. ...

The medial surface (facies medialis; internal surface) is broad and concave above, narrow and convex below. Its upper three-fourths give origin to the Flexor digitorum profundus; its lower fourth is subcutaneous.

Additional images

Bones of left forearm. Posterior aspect. Image File history File links Download high resolution version (717x1254, 103 KB) File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ...

This article was originally based on an entry from a public domain edition of Gray's Anatomy. As such, some of the information contained herein may be outdated. Please edit the article if this is the case, and feel free to remove this notice when it is no longer relevant. The public domain comprises the body of all creative works and other knowledge—writing, artwork, music, science, inventions, and others—in which no person or organization has any proprietary interest. ... An illustration from the 1918 edition Henry Grays Anatomy of the Human Body, commonly known as Grays Anatomy after Henry Gray, is an anatomy textbook widely regarded as a classic work on human anatomy. ...