MUSCLES OF THE TRUNK. 



245 



arch, where it forms adhesions. It has been described, in human anatomy, 

 as the fascia transversalis. 



Action. It compresses the abdominal viscera when it contracts, and 

 presses them against the vertebral column. 



DIFFERENTIAL CHARACTERS 

 OF THE MUSCLES OF THE 

 ABDOMINAL REGION IN 

 OTHER THAN SOLIPED 

 ANIMALS. 



As has been already 

 said, the development of the 

 abdominal tunic is in pro- 

 portion to the volume of 

 the digestive viscera. This 

 membrane is, therefore, 

 very wide and thick in 

 Ruminants, while it is re- 

 duced to an insignificant 

 leaf in the Pig and Car- 

 nivora. In these animals 

 the internal crural aponeu- 

 rosis does not exist, and 

 is replaced by a eel lulu r 

 layer. The aponeurosis of 

 the great oblique, instead of 

 being doubled into two 

 laminae at its posterior 

 border, is entirely reflected 

 to form the crural arch. 

 In the latter animals, the 

 great oblique is also dis- 

 tinguished by the extensive 

 development of its mus- 

 cular part, and the narrow- 

 ness of its aponeurosis. 



The muscular portion 

 of the small oblique of Ru- 

 minants occupies the entire 

 space comprised between 

 the posterior border of the 

 last rib, the extremity of MUSCLES OF THE ANTERIOR ASPECT OF THE BODY OF MAN; 

 the transverse processes of ON THE LEFT SIDE THE SUPERFICIAL LAYER is SEEN, ON 

 the lumbar vertebrae, and THE RIGHT THE DEEPER LAYER. 



the external angle of the 1 ? Pectoralis major; 2, Deltoid; 3, Anterior border of the 

 ilium. The small retractor latissimus dorsi ; 4, Serratus magnus ; 5, Subclavius, right 

 side ; 6, Pectoralis minor ; 7, Coraco-brachialis ; 8, Biceps, 

 with its two heads; 9, Coracoid process of the scapula; 10, 

 Serratus magnus, right side ; 11, External intercostal muscle 

 of the fifth intercostal space ; 12, External oblique ; 13, Its 

 aponeurosis with the linea alba ; 14, Poupart's ligament ; 

 15, External abdominal ring; 16, Rectus muscle of right 

 side; 17, Pyramidalis muscle; 18, Internal oblique; 19, 

 Conjoined tendon of internal oblique muscle and Poupart's 

 ligament. 



of the last rib is not distinct 

 from the principal muscle. 

 This arrangement is like- 

 wise present in the smaller 

 domesticated animals. It 

 is also to be remarked that, 

 in Ruminants, the tendinous 

 intersections of the great 

 rectus muscle of the abdomen 



are more marked at its 



superior than its inferior face ; and that the aponeurosis of the transverse is much thicker 



and more resisting than in Solipeds. 



COMPARISON OF THE ABDOMINAL MUSCLES OF MAN WITH THOSE OF ANIMALS. 



With the exception of some slight differences, the abdominal muscles of Man present 

 the same disposition as Ihose of the smaller animals. 



The abdominal tunic is not present, but is replaced by a cellular layer which 



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