414 



DISSECTION OF THE ABDOMEN. 



O 



Fig. 138. 



ribs, viz., by tendon from the lowest two, and by fleshy processes from 

 the under surface of the cartilages of the four next above. And between 

 the chest and the pelvis it is connected with the lumbar vertebra? by means 

 of the posterior aponeurosis or the fascia lumborum. All the fibres are 

 directed to the aponeurosis in front. 



Its anterior aponeurosis is widest below, as in the most external muscle. 

 Internally it is continued to the linea alba, passing beneath the rectus as 

 low as midway between the umbilicus and the pubes, but in front of the 

 muscle below that spot. Its attachment below to the pelvis is nearly the 

 same as the internal oblique ; for it is fixed to the front of the pubes' and 



to the pectineal line for about an 

 inch, but beneath the oblique muscle : 

 some of the fibres are spent on the 

 transversalis fascia, and are con- 

 nected with a thickened band of that 

 fascia beneath Poupart's ligament, 

 which is called the deep crural arch. 

 Action. The chief use of the 

 muscle will be applied to diminish- 

 ing the size of the abdominal cavity, 

 and compressing the viscera ; but it 

 will assist the internal oblique in re- 

 placing the viscera pushed down in 

 inspiration. 



Conjoined tendon. The aponeu- 

 rosis of the internal oblique and 

 transversalis muscles are united 

 more or less near their attachment 

 to the pubes, and give rise to the 

 conjoined tendon. The aponeurosis 

 of the oblique muscle extends about 

 half an inch along the pectineal line ; 

 whilst that of the transversalis 

 reaches an inch along the bony 

 ridge, and forms the greater part of 

 the conjoined tendon. 



The posterior aponeurosis of the 

 transversalis, or the fascia lumbo- 

 rum, c, is described in the dissection 

 of the Back, p. 357. 



Connections. Superficial to the 

 transversalis are the two muscles be- 

 fore examined ; and beneath it is 

 the thin fascia transversalis. Its 

 fleshy attachments to the ribs digi- 

 tate with like processes of the diaphragm. The lower border is fleshy in 

 the outer, but tendinous in the inner half, and is arched above the internal 

 abdominal ring. 



Dissection. To remove the aponeurotic layer from the rectus muscle 

 of the right side, make a longitudinal incision through the tendinous 

 sheath, and turn it to each side. As the fascia is reflected, its union with 

 three or more tendinous bands across the rectus will have to be cut 

 through ; and near the pubes a small muscle, the pyramidalis, will be ex 



DISSECTION OF THE THIRD LATERAL MUSCLE 

 i.v THE WALL OF THE BELLY, with the ves- 

 sels and nerves on it. 



A Transversalis muscle, with B, its anterior, 

 and c, its posterior tendon (fascia lum- 

 borum). 



D. Poupart's ligament. 

 1. Last dorsal nerve with its accompanying 



artery. 



'2. Ilio-hypogastric nerve with its artery, 

 ft Intercostal neves and arteries. 



