Trochlear notch

Semilunar notch

Upper extremity of left ulna. Lateral aspect. (Semilunar notch visible at center top.)
Details
Latin Incisura trochlearis ulnae,
incisura semilunaris ulnae
Identifiers
Gray's p.215
Dorlands
/Elsevier
i_05/12447565
TA A02.4.06.006
FMA 23619
Anatomical terms of bone

The semilunar notch of the ulna (trochlear notch of ulna, greater sigmoid cavity) is a large depression, formed by the olecranon and the coronoid process, and serving for articulation with the trochlea of the humerus.

About the middle of either side of this notch is an indentation, which contracts it somewhat, and indicates the junction of the olecranon and the coronoid process.

The notch is concave from above downward, and divided into a medial and a lateral portion by a smooth ridge running from the summit of the olecranon to the tip of the coronoid process.

The medial portion is the larger, and is slightly concave transversely; the lateral is convex above, slightly concave below.

References

This article incorporates text in the public domain from the 20th edition of Gray's Anatomy (1918)

External links