454: PRACTICAL ANATOMY. 



rectum; the base is below; it is formed of the trans- 

 versus perinei, sphincters of the vagina and rectum 

 where they are attached to the central tendon, and a 

 mass of nbro-muscular tissue of variable height and 

 thickness. Numerous arteries and veins, branches of 

 the pudic and haemorrhoidal, supply the perineum ; it 

 is also freely supplied with nerves communicating with 

 the uterine and pelvic plexuses of the sympathetic. 



SCARPA'S TRIANGLE. 



Scarpa's triangle is situated at the upper anterior por- 

 tion of the thigh ; it is bounded above by Poupart's 

 ligament, externally by the sartorius muscle, internally 

 by the adductor longus. Its floor is formed from within 

 outward by the pectineus, psoas magnus, and iliacus. 

 The femoral vein, artery, and crural nerve pass from the 

 middle of Poupart's ligament to the apex of the tri- 

 angle ; the vein is to the inner side, the artery in the 

 middle, and the nerve externally. The artery and vein 

 are inclosed in a sheath ; the nerve is to the outer side. 

 Near the anterior superior spine of the ilium emerges 

 the external cutaneous nerve, and passes to the skin 

 along the outer side of the thigh. Just after its exit 

 from beneath Poupart's ligament, the anterior crural 

 nerve breaks up into superficial cutaneous and deep mus- 

 cular branches. One of the latter the long saphenous 

 passes down the thigh with the femoral artery. About 

 two inches below Poupart's ligament the femoral artery 

 gives off the profunda, which supplies the muscles of 

 the thigh. The femoral continues down the thigh and 

 becomes the popliteal. The femoral vein receives numer- 

 ous venous radicles ; the most important branch is the 

 long saphenous, which drains the superficial structures 

 from the ankle to the groin. 



