- LBS 01 THE TRT'XK. ''" 



II. MUSCLES OF THE TRUNK. 



I. MUSCLES OF THE ABDOMEX. 



In the formation of the abdominal wall the following muscles 

 take part : (i) m. reef us aldominis. (2) ///. oUlqinis eztennts, (3) m. 

 oUiqiu/s intenius, (4) the portia aldominalis of the m. pectoral**. 

 Above, the ///. oll'inuus Internus forms a kind of diaphragm, partially 

 separating the abdominal from the thoracic cavity (p. 70). 



28. 37. reef us aldominis (Fig. 62 r). 



Duges. pubio-thoracique, n. 52. 



These muscles, situated on either side of the middle line of the 

 abdomen, are as a rule traversed by five notched itucriplioncM ten- 

 dineae. Each muscle arises, by a narrow, strong tendon, from the 

 inferior border of the pubes. passes forwards, and quickly widening, 

 divides at the second interipiio fendlnta (counting from behind) into 

 two portions. 



(a) The Outer portion (Fig. 62 r) runs into the portlo a&dominalis of 

 the ;//. pecforalis, and forms the greater lateral division of that muscle. 



() The Inner (/) continues as the m. rectv* abdominu and gradu- 

 ally narrows anteriorly. At the sternum some of the fibres (the 

 median) are inserted into the dorsal surface of the cartilaginous 

 plate of the xiphisternum, while the greater part of the muscle con- 

 tinues forwards over the coracoid to become the ///. dento&yoidau 

 at about the fifth uucriptio lendinea (p. 64). 



29. 37. oUiquv.* externns (Fig. 63 oe, oe\ 



Zenker, I.e., p. 31, m. oUiq'nm. Duges, dorso-sous-abdominal, n. 54. 



The w. oW.lqinis extenms arises from 



(a) The aponeurosis covering the long muscles of the back, and 

 by this from the spinous processes. The anterior edge of the 

 ///. olliqitns externus covers the posterior edge of the //>. latizs'uniis 

 florsi, which arises from the inferior, ventral surface of the aponeu- 

 rosis. The aponeurosis also divides laterally into two parts, one of 

 which, the posterior, passes into the obliquits ext emits, while the 

 anterior forms the tendon of origin of the depressor n/axiUae if. 

 (dm} (compare Fig. 66). 



(h} A second, narrow portion, port in onio-abdominalix (Fig. 63 oe'J 



F 2 



