S20 MUSCLES OF THE ABDOMEX 



fascia, termed crcmasfrric, which adheres to the fascia propria of the 

 testicle. Sometimes tlie only fibres developed are a bundle descending 

 from the outer attachment. 



In the female there may be almost constantly detected a small Imndle of fibres 

 descending on the round ligament of the uterus, which coiTespond with the last- 

 mentioned fibres of the cremaster muscle of the male. 



The transversalis abdominis muscle, subjacent to the internal 

 oblique, arises from the inner surface of the cartilap;es of the six lower 

 ribs ; from a strong aponeurosis attached to the lumbar vertebrte ; from 

 the inner margin of the crest of the ilium in the anterior two-thirds of 

 its extent, and from the iliac third of Poupart's ligament. The greater 

 part of the fibres have a horizontal direction, and extend forwards to a 

 broad aponeurosis in front ; the lowest fibres curve downwards like 

 those of the internal oblique, and are inserted into the front of the 

 pubis and into the pectineal line, through the medium of the conjoined 

 tendon already described as common to this muscle and the internal 

 oblique. 



The anterior aponeurosis of the transversalis muscle commences in the 

 greater part of its extent at the distance of about an inch from the 

 outer border of the rectus muscle ; but at its upper extremity it is much 

 narrower, and there the muscular fibres of opposite sides approach 

 nearly to the middle line behind the recti muscles. It becomes united 

 with the posterior layer of the aponeurosis of the internal oblique 

 forming the posterior wall of the rectus sheath, and inferiorly, where 

 that aponeurosis passes entirely in fi'ont of the rectus muscle, it passes 

 likewise in front of that muscle. 



The posterior aponeurosis of the transversalis muscle extends back- 

 wards between the last rib and the iliac crest, and opposite the outer 

 border of the erector spinte muscle, becomes continuous with the lumbar 

 aponeurosis. 



l'(fri('ti<v. — The transversalis has been found fused with the internal oblique 

 (Soemmering) ; or entirely absent (IMacalister). The spermatic cord has been 

 seen to pierce its lower border (Guthrie). 



The rectus abdominis is a long flat muscle, consisting of vertical 

 fibres, situated at the fore part of the abdomen, within a tendinous 

 sheath, formed in the manner already described in the account of the 

 aponeurosis of the internal oblique muscle ; it is separated from the 

 muscle of the other side by a narrow interval, which is occupied by a 

 dense fibrous structure, the tinea alba afterwards described. It arises 

 from the upper margin of the pubis by a flat tendon consisting of two 

 parts, of which the internal is much the smaller, and is connected with 

 the ligaments covering the pubic symphysis, while the external one is 

 fixed to the pubic crest. Expanding and becoming thinner at the 

 upper end, the muscle is inserted into the cartilages of three ribs, the 

 fifth, sixth, and seventh, usually by three distinct parts of unequal 

 size. Some fibres also are generally found attached to the ensiform 

 cartilage. 



The fibres of the rectus muscle are interrupted by three or more 

 irregular tendinous intersections, named tinece tramversic. The three 

 which are most constant are placed, one opposite the umbilicus, another 

 on a level with the ensiform cartilage, and the third intermediately 

 between them : and these generally run across the whole muscle. 



