334 



ABDOMINAL MUSCLES. 



Fig. So.* it is so particularly well adapted 



for the latter purpose, that it 

 might be called the projitr con- 

 strictor of the abdomen. 



The long muscle in the middle 

 is named 



Rectus Abdominis, 



Arises, by two heads, from the 

 ligament of the cartilage which 

 joins the two ossa pubis to each 

 other; runs upwards the whole 

 length of, and parallel to the linea 

 alba, growing broader and thin- 

 ner as it ascends. 



Inserted into the cartilages of 

 the three inferior true ribs, and 

 often intermixed with some fibres 

 of the pectoral muscle. 



It is generally divided by three 

 first is at the umbilicus ; the 

 the cartilage of the seventh rib ; 

 and the third in the middle between these ; and there is 

 commonly a half intersection below the umbilicus. These 

 intersections (linece transversa) seldom penetrate through 

 the whole thickness of the muscle : they adhere firmly to the 



tendinous intersections : the 

 second, where it runs over 



* A lateral view of the trunk of the body, showing its muscles, and particu- 

 larl)' the transversalis abdominis. ]. The costal origin of the lattissimus dorsi 

 muscle. 2. The serratus magnus. 3. The upper part of the external oblique 

 muscle divided in the direction best calculated to show the muscles beneath 

 without interfering with its indigitations with the serratus magnus. 4. Two of 

 the external intercostal muscles. 5. Two of the internal intercostals. 6. The 

 transversalis muscle. 7. Its posterior aponeurosis. S. Its anterior aponeurosis 

 forming the most posterior layer of the sheath of the rectus. 9. The lower part 

 of the left rectus with the aponeurosis of the transversalis passing in front. 

 10. The right rectus muscle. 11. The arched opening left between the lower 

 border of the transversalis muscle and Poupart's ligament, through which the 

 spermatic cord and hernia pass. 12. The gluteus raaximus, and medius, and 

 tensor vaginae femoris muscles invested by fascia lata. 



