698 



THE VASCULAR SYSTEMS 



nor internal 



external lateral ligament, and the tendon of the Biceps muscle, and divides into 

 branches which anastomose with the inferior internal articular artery, the superior 

 external articular artery, and the anterior recurrent branch of the anterior tibial. 



Circumpatellar Anastomosis. - 

 Around and above the patella, and 

 on the contiguous ends of the femur 

 and tibia, is a large network of vessels, 

 forming a superficial and a deep 

 plexus. The superficial plexus is 

 situated between the fascia and skin 

 around about the patella; the deep 

 pj exuSj w hich forms a close network 

 of vessels, lies on the surface of the 

 lower end of the femur and upper 

 end of the tibia around their articular 

 surfaces, and sends numerous off- 

 shoots into the interior of the joint. 

 The arteries from which this plexus 

 is formed are the two internal and 

 two external articular branches of the 

 popliteal, the anastomotica magna, 

 the terminal branch of the profunda, 

 the descending branch from the ex- 

 ternal circumflex, and the anterior re- 

 current branch of the anterior tibial. 



The Anterior Tibial Artery (A. 

 Tibialis Anterior) (Fig. 485). 



The anterior tibial artery com- 

 mences at the bifurcation of the 

 popliteal at the lower border of the 

 Popliteus muscle, passes forward be- 

 tween the two heads of the Tibialis 

 posticus, and through the large oval 

 aperture above the upper border of 

 the interosseous membrane to the 

 deep part of the front of the leg; it 

 here lies close to the inner side of the 

 neck of the Jfibuja; it then descends 

 on the anterior surface of the inter- 

 osseous membrane, gradually ap- 

 proaching the tibia; and at the lower 

 part of the leg lies on this bone, and 

 then on the anterior ligament of the 

 ankle to the bend of the ankle-joint, 

 where it lies more superficially, and 

 becomes the dorsalis pedis. 



H -ft Communicating. 



tib.al and 



Relations. In the upper two-thirds of 

 its extent it rests upon the interosseous 

 membrane, to which it is connected by deli- 

 cate fibrous arches thrown across it; in the 



