MUSCLES OF THE ANTERIOR LIMBS. 



S21 



^ig. 182. 



It is oblique downwards and backwards, pyriform, enlarged at its superior 

 extremity, contracted inferiorly, where it terminates by two small flat tendons. 



Attachments. — It originates, by its superior extremity, from the inner aspect 

 of the humerus, behind and above the tuberosity on its body. One of its 

 terminal tendons is attached to the summit of the 

 olecranon ; the other glides over a small convexity 

 on the inner side of that eminence, and goes to be 

 inserted a little lower than the first. 



Relations. — Above, with the inferior border of the 

 large extensor ; outwards, with the humerus, the 

 short flexor, and short extensor of the forearm ; in- 

 wards, with the humeral insertion of the latissimus 

 dorsi and the abductor of the arm, the long branch 

 of the flexor brachii, the vessels and nerves on the 

 inner side of the arm, and the long extensor of the 

 forearm. 



Action. — An extensor of the forearm. 



4. Small Extensor of the Fokearm or 

 Anconeus (Fig. 128, 10). 



Synonym. — Humero-olecranius minor — Girard. 



Form — Structure — Situation — Relations. — 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 outwards. 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 Characters in the Muscles of the Arm 

 IN THE other Animals. 



In all animals, the long flexor of the forearm, or flexor 

 brachii, is less thick and tendinous than in Solipeds. 



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 tuberosity, and also furnishes a small 

 tendinous branch which glides over the inner side of the 



deep muscles on 

 ternal aspect 



anterior LIMB. 



THE EX- 



)f right 



1, Scapula; 2, coracoid process 

 of scapula ; 3, flexor brachii ; 

 4, superior extremity of humerus ; 5, external tuberosity of humerus ; 6, humeralis obliquus ; 

 7, body of humerus ; 8, biceps ; 9, anterior, or great extensor of the metacarpus ; 10, ulna ; 

 11, extensor pedis, or anterior extensor of the phalanges; 12, ulnaris accessorius, or ulnar portion 

 of the perforans ; 13, lateral extensor of the metacarpus, 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; 19, perforatus tendon; 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. 



