THE RADIUS 91 
is correspondingly concave in its length and is flattened in the transverse direction. 
At its proximal part there is a smooth shallow groove, which concurs with the ulna 
in the formation of the interosseous space of the forearm (Spatium interosseum 
antibrachii); the nutrient foramen is in the lower part of this groove. Below this 
there is in the young subject a narrow, rough, triangular area to which the ulna is 
Olecranon 
Processus anconeus 
Semilunar notch 
Humeral articular 
YEE: A 
Coronoid VS 
process ae 
Radial tu- 5 ech 
berosily 
Interosseous 
space 
Fic. 67 —Lerr Rapivus anp Utna or Horse; Lateran 
View. 
1, Tuberosity for attachment of lateral ligament of 
elbow joint, and common and lateral extensor muscles; 
2, tuberosity for attachment of lateral ligament of 
¢arpal joint; 3, groove for common extensor tendon; 
4, groove for lateral extensor tendon. 
Processus 
_ anconeus 
Semilunar notch 
Glenoid cavity 
Olecranon 
Radial 
tuberosity 
Shaft of ulna 
Interosseous 
space 
Shaft of radius 
Ridge 
Carpal articular 
surface 
Fic. 68.—Lerr Rapivs anp Utxa or Horse; Meprar 
VIEw. 
1, Tuberosity for attachment of short part of 
medial ligament of elbow; 2, prominence for long part 
of same; 3, groove for end of brachialis muscle; 4, 
tuberosity for attachment of medial ligament of carpal 
joint; 5, oblique groove for tendon of extensor carpi 
obliquus. 
attached by an interosseous ligament; in the adult the two bones are fused here. 
A variable rough elevation distal to the middle and close to the medial border gives 
attachment to the radial check ligament. The medial border (Margo medialis) 
is slightly concave in its length and is largely subcutaneous; at its proximal end 
there is a smooth area on which the tendon of insertion of the brachialis muscle lies, 
and a small rough area just below gives attachment to that muscle and the long 
