THE MUSCLES. 151 



the round ligament in the female), which perforates the anterior 

 abdominal parietes formed of the three preceding muscles, is l 

 to 2" long, and passes in the direction of lig. Poupartii, obliquely 

 from above, outwards and backwards, downwards, inwards and 

 forwards. M. obliq. extern, forms its inferior and anterior wall, 

 its posterior thefasc. transv. and tendinous fibres of obliq. intern. 

 and transv. (towards the annul, abdominal.)', its superior, the 

 inferior borders of mm. obliq. intern, and transv. The interior 

 of the canal is lined by fasc. trans, \_fasc. spermatica intern^], 

 which continues down into the scrotum as a common envelope of 

 the spermatic cord and testicle. Behind it opens into the abdo- 

 minal cavity by means of the irregular 



260. Annulus inguinalis internus (at a distance of 2" from 

 the spina ilei sup.), on the internal semilnnar sharp border of 

 which (plica semilunaris of the fas c. transv.) the Art. epigas- 

 trica passes upwards and inwards. Through this ring, in the 

 mature foetus, the testicle, together with the spermatic cord, passes 

 out from the abdominal cavity into the inguinal canal, and thence 

 into the scrotum. At birth the annul, inguinal, intern, and 

 extern, lie close behind one another. 



261. Linea alba is the white stripe found in the central line of 

 the abdominal parietes, in which the aponeuroses of the lateral 

 abdominal muscles are associated together (or decussate, Velpeau), 

 which passes downwards from Proc. ensiform. as far as Symph. 

 pubis, between the mm. recti, above the umbilicus 3 to 2"', at it 

 |", below it 1'" broad. The navel ring, annulus umbilicalis, is 

 a large (rhombic, Velpeau) opening in about [below] the centre, 

 through which in the (new-born) infant the umbilical vessels (fre- 

 quently also portions of intestine) pass. On the anterior surface 

 the white line is stretched by the m. pyramidalis ; on the pos- 

 terior surface it is strengthened by the lig. triangulare s. admini- 

 culum lin. albx, the apex upwards. 



Nerves : (first to the third) intercostales, lumbales, iliohypogastricus. 



262. 4. Rectus abdominis. 



Pos. : close to [the outer side of] the linea alba [on the inside 

 of linea semilunaris, a curved tendinous line, extending from the 

 cartilage of the eighth rib to the tuberosity of the os pubis~], in 

 the very strong vagina recto-abdominalis. Fig. : elongated, flat, 

 with two to six tendinous transverse striae, inscriptiones tendinse. 

 Or. : Symph. oss. pubis (with two tendons). Ins. : fifth to seventh 

 rib cartilages (anterior surfaces), Proc. ensiformis. Use : to 

 compress the abdominal viscera ; to draw the sternum and the 

 fifth to seventh ribs downwards (exspiratio), or, to flex the pelvis. 



