260 



THE MUSCLES. 



Fig. 122. 



and nerves on the inner side of the arm, and 

 the long extensor of the fore-arm. 



Action. An extensor of the fore-arm. 



5. Small Extensor of tlie Fore-arm or Anconeus. 

 (Fig. 85, 10.) 



Synonym. Humero-olecranius minor Girard. 



Form Structure Situation Eelations. 

 This is a small, thick, and prismatic muscle, 

 almost entirely fleshy, situated behind the elbow 

 articulation. It is applied against the synovial 

 cul-de-sac which ascends into the olecranian 

 fossa, and to which it is strongly attached ; it 

 is hidden by the short extensor, from which it is 

 not easily distinguished. 



Attachments. It originates from the margin 

 of the olecranian fossa, chiefly above and out- 

 wards. It terminates by being inserted into the 

 anterior and external part of the olecranon. 



Action. This little muscle, a congener of the 

 preceding, raises the articular capsule it covers, 

 and prevents its being pinched between the bony- 

 surfaces. 



DIFFERENTIAL CHAEACTERS OF THE MUSCLES OF THE 

 A KM IN OTHER THAN SOLIPED ANIMALS. 



In all animals, the long flexor of the fore-arm, or 

 coraco-radialis, is less thick and tendinous than in Soli- 



In the Pig, Dog, and Cat, it comports itself in a 

 special manner at its inferior extremity ; it is attached 

 at first to the bicipital tuberodty, and also furnishes a 

 small tendinous branch which glides over the inner side 

 of the radius by means of a synovial bur=a, and is fixed 

 within the ulna, towards the base of the olecranon. 



The short flexor of the fore-arm, or anterior brachial, 

 is terminated, in the Pig, Dog, and Cat, by a small 

 tendon which is fixed in the ulna, below the ulnar 

 branch of the coraco-radialis. 



The long extensor of the fore-arm, which is found in 

 all the domesticated animals, arises from the external face 

 of the great dorsal in the Pig and Dog. The middle 

 extensor of the fore-arm and anconeus of these animals 

 are remarkable for their volume. 



COMPARISON OF THE MUSCLES OF THE ARM OF MAN 

 WITH THOSK OF ANIMALS. 



In Man, three muscles are situated in front of the 



DEEP MUSCLES ON EXTERNAL 

 ASPECT OF RIGHT ANTERIOR 

 LIMB. 



1., Scapula; 2, Coracoid process 

 of scapula ; 3, Flexor brachii ; 

 4, Superior extremity of humerus ; 5, External tuberosity of humerus ; 6, Humeralis 

 externus ; 7, Body of humerus ; 8, Biceps ; 9, Anterior, or great extensor of the meta- 

 carpus; 10, Ulna, 11, Extensor pedis, or anterior extensor of the phalanges; 12, Ulnaris 

 accessories, or ulnar portion of the perforans ; 13, Lateral extensor of the metacar- 

 pus, or extensor suffraginis ; 14, Oblique extensor of the metacarpus ; 15, Flexors of 

 the foot; 16, Trapezium, 17, Annular ligament; 18, Carpal ligament of perforans 

 tendon, 20; i9, Perforatus; 21, Tendon of anterior extensor of metacarpus; 22, Small 

 metacarpal bone ; 23, Suspensory ligament ; 24, Lateral band of metacarpo-phalangeal 

 sheath , 25, Perforans tendon ; 26, Branch of the suspensory ligament joining the 

 extensor pedis, 27. 



