332 ABDOMINAL MUSCLES. 



producing expiration and its various modifications of coughing, 

 sneezing, &;c. 



They bend the spine forwards, or approach the thorax to the 

 pelvis. 



When one acts separately, it bends the trunk obliquely to 

 the side on which it is situated. 



3. Obliquus Ascendens Internus, 



Arises from the spine of the ilium the whole length between 

 the posterior and superior anterior spinous process ; from the 

 OS sacrum and the three undermost lumbar vertebrae, by a 

 tendon, (^fascia lumborum) common to it, to the serratus 

 posticus inferior muscle, and to the latissimus dorsi ; from 

 Poupart's ligament, at the middle of which it sends off the 

 beginning of the cremaster muscle ; the spermatic chord in the 

 male, or round ligament of the womb in the female, passes 

 under its thin edge, with the exception of a few detached 

 fibres. 



Inserted into the cartilago-ensiformis, into the cartilages of 

 the seventh, and those of the false ribs ; but, at the upper part, 

 it is extremely thin, resembling a cellular membrane, and only 

 becomes fleshy at the cartilage of the tenth rib. Here its 

 tendon divides into two layers; the anterior layer, with a great 

 portion of the inferior part of the posterior layer, joins the 

 tendon of the external oblique, and runs over the rectus to be 

 inserted into the whole length of the linea alba. The posterior 

 layer joins the tendon of the transversalis muscle as low as 

 half way between the umbilicus and os pubis ; but, below this 

 place, only a kw fibres of the posterior layer are seen, and the 

 rest of it passes before the rectus muscle, and is inserted into 

 the linea alba ; so that the whole tendon of the external 

 oblique muscle, with the anterior layer of the internal oblique, 

 passes before the rectus muscle ; and the whole posterior 

 layer of the internal oblique, together with the whole tendon 

 of the transversalis muscle, excepting at the inferior part, 

 passes behind the rectus, and is inserted into the linea alba. 

 At its undermost part, it is inserted into the forepart of the os 

 pubis. 



