ABDOMEN. 



ilii, the fibres arise from a tendinous lamella, 

 which itself is trifoliate in its origin. This ten- 

 don is found as an undivided lamella between 

 the outer margin of the quadratus lamborum and 

 the commencement of the fleshy fibres of the 

 muscle, extending vertically from the last rib 

 to the crista ilii. ( Fig. 4, 1.) The three laminae 

 of which this tendon is composed arise from 

 different portions of the vertebrae in the lumbar 

 region of the spine; the posterior, which is 

 thick and strong, and is commonly called 

 fascia lumborum, arises from the extremities 

 of the spinous processes, and covers the lum- 

 bar mass of muscles. (Fig. 4, g.) The mid- 

 dle, which is weak, is attached to the apices of 

 the transverse processes ; it lies in front of the 

 lumbar mass and behind the quadratus lumbo- 

 rum (Jig. 4, h); and the anterior arises from the 

 pedicles which connect the transverse processes 

 to the bodies of the vertebrae, and covers the 

 quadratus lumborum muscle in front (Jig. 4, 

 f). Inferiorly, the transversalis muscle at- 

 taches itself to the inner lip of the crista ilii 

 for its three anterior fourths, and to the ex- 

 ternal third or half of Poupart's ligament, cor- 

 responding to the attachments of the obliquus 

 internus. The fleshy fibres of the muscle pass 

 from these several points of attachment trans- 

 versely inwards, the middle being the longest, 

 and the superior the shortest, and are in- 

 serted into the outer convex margin* of a 

 tendinous aponeurosis, which extends to the 

 linea alba. This aponeurosis is intimately 

 connected with the posterior division of that 

 of the obliquus internus for an extent corre- 

 sponding to the three superior fourths of 

 the rectus muscle, behind which both pass to 

 be inserted into the ensiform cartilage and 

 linea alba, (Jig. 4, a,) forming the posterior 

 wall of the sheath of the rectus. Inferiorly, as 

 we have already remarked, these conjoined 

 tendons go together in front of the rectus, and 

 are inserted into the inferior fourth of the linea 

 alba and into the pubis. At the inner extre- 

 mity of the inguinal canal, it will be seen by 

 carefully raising up the spermatic cord, that 

 this union of the tendons of these two muscles 

 ceases, and we can trace the fibres of the trans- 

 versalis tendon passing down in a curved direc- 

 tion, more curved as they are more external, 

 and insinuating themselves behind the cord to 

 be inserted into Gimbernat's and Poupart's 

 ligament for about its ^xternal third or fourth. 

 This mode of insertion of the transversalis ten- 

 don was first described by Sir Astley Cooper, f 

 and these fibres were by him called thejblded 

 fibres of the transversalis. They adhere to the 

 subjacent fascia, (fascia transversalis,) and add 

 to the strength of the inner portion of the pos- 

 terior wall of the inguinal canal. They cor- 

 respond, in a great measure, to the external 

 abdominal ring, and may be counted as one of 

 the obstacles provided against the direct descent 

 of a hernia. 



Such is unquestionably the usual mode of 



* This margin forms the linea semilunaris of 

 Spigelius. 



t Cooper on the Testicle, p. 35. 



insertion of the tendon of the transversalis 

 muscle ; but Mr. Guthrie has lately called the 

 attention of anatomists to a variety which it 

 is important to know, although it cannot be 

 of frequent occurrence. In this variety the 

 spermatic cord appears to pass through a slit in 

 the inferior margin of the transversalis muscle, 

 so that a bundle of muscle passes behind as 

 well as before the cord ; the posterior one end- 

 ing in tendinous fibres, which, like the folded 

 fibres above described, are inserted into Pou- 

 part's ligament.* It is very generally believed 

 that the inferior fibres of this muscle contribute, 

 as well as those of the obliquus internus, to 

 form the cremaster. The two muscles are so 

 closely connected externally by their inferior 

 margins, that it is natural to suppose that both 

 do send fibres to the cremaster. Sir Astley 

 Cooper expresses the relation of the cremaster 

 to these two muscles in the clearest way, when 

 he says that it arises from Poupart's ligament 

 within the inguinal canal, and there blends with 

 some of the fibres of both these muscles.f 



A thin layer of cellular tissue covers the 

 transversalis muscle, and separates it from the 

 obliquus internus. At its superior margin it 

 is intimately related to the diaphragm, and 

 some of its fibres seem to be continuous with 

 it : posteriorly, by the triple partition of its 

 tendon, it ensheaths the lumbar muscles, and it 

 lies upon the fascia transversalis, which, with a 

 layer of cellular tissue, separates it from the 

 peritoneum. | 



4. Rectus abdominis (ster no-pub ien). After 

 the superficial fascia has been removed so as 

 to expose the aponeurosis of the external ob- 

 lique, the recti muscles are seen on either side 

 of the middle line covered by this aponeurosis, 

 which it is necessary to slit up in order to ex- 

 pose the muscles. The rectus owes its name 

 to the perpendicular course of its fibres, which 

 pass from the pubis to the thorax, nearly 

 parallel to the middle line. It is long and 

 narrow ; however, its breadth increases as it 

 advances upwards, and as it increases in breadth 

 it diminishes in thickness. At the pubis the 

 muscle has its most fixed point of attachment, 

 whence it is generally said to have its origin 

 there: it arises by a short tendon from the 

 symphysis of the pubis; this tendon is very 

 narrow at its origin, but soon expands, and 

 unites with the muscular fibres, which pass 

 vertically upwards to the lower margin of 

 the thorax, where the muscle is considerably 

 increased in breadth, and divides into three 

 portions; the first or internal one is inserted 

 into the costoxiphoid ligament and cartilage 

 of the seventh rib ; the middle, larger than 

 the preceding, into the cartilage of the sixth 

 rib at its inferior edge and anterior surface; 



* Guthrie on Inguinal and Femoral Hernia, pp. 

 11, 12, 13, 4to. Lond. 1833. 



t Op. cit. p. 38. 



t " The transversalis corresponds, by the direction 

 of its fibres, to the ' triangularis sterni ;' also, by its 

 situation, by the attachment of its external edge to 

 the internal surface of the ribs, and by that of its 

 internal edge to the sternum and linea alba." 

 Mechel. 



