318 



MUSCLES OF THE ABDOMEN. 



2-24. 



/i^^^^-^ 



of the rectus muscle. The deficiency thus resulting in the posterior 

 wall of the sheath of the rectus muscle is marked superiorly by a well- 

 defined lunated edge, whose concavity looks downwards towards the 

 pubis — the semilunar fold of Douglas. 



delations. — The internal oblique 

 muscle is almost entirely covered 

 by the external oblique. A small 

 angular portion only near the place 

 where its posterior fibres take their 

 origin, under cover of the latissi- 

 mus dorsi, is exposed between 

 that muscle and the external ob- 

 lique, and even this is not con- 

 stantly found. 



Fig. 224.— Later.^-l View of the 

 Muscles op the Abdomen and 

 Tkunk, the Ikternal Oblique 

 Muscle having been exposed 

 by the re3i0val of the external 

 Oblique (modified from Henle). 

 (A. T.) \ 



a, anterior sxiperior spinous process 

 of the ilium ; b, trochanter major ; 

 c, spine of piibes ; d, lumbar fascia; 

 VI to XII, the sixth to the twelfth 

 ribs ; 1 , lower part of the gi-eat pec- 

 toral muscle, where it is attached to 

 tlie external oblique muscle ; 2, 2, 

 lower digitations of the serratus mag- 

 nus from the fourth to the eighth ribs ; 

 3, lower costal attachments of the 

 latissimus dorsi ; 3', its iliac attach- 

 ment ; 4, trapezius ; 5, divided attach- 

 ments of the external oblique, left in 

 connection with the ribs ; 5, aponeu- 

 rosis of the external oblique divided in 

 front of the rectus, where it joins the 

 sheath ; 6, internal oblique at its 

 middle ; 6', 6', line where it divides 

 to form the sheath of the rectus ; 

 + + ■¥ XII, its attachment to the 

 four lowest ribs ; 6", the conjoined 

 tendon, and above, and to the out- 

 side, the internal inguinal aperture ; 

 7, sartorius ; 8, rectus femoris ; 9, 

 tensor vagina femoris ; 10, gluteus 

 medius ; 11, gluteus maximus. 



Varieties. — A iibrous inscription 

 is frequently seen in the upper 

 part of this muscle prolonged for- 

 ward from the point of the tenth rib, and a slender cartilaginous slip jjerfectly 

 separate from that of the rib has been seen Ijdng in this inscription. (Henle.) 

 An inscription opposite the eleventh rib is described by Macalister. 



The cremaster, a muscle peculiar to the male, consists of fibres 

 lying in series with those of the lower border of the internal oblique 

 muscle. It presents an external and an internal attachment. The 

 external attachment is to the inner end of Poupart's ligament, and 

 there its fibres are continuous with those of the internal oblique muscle ; 



