THE EXTERNAL ILIAC ARTERIES. 



643 



Popliteal artery. — This artery gives an iimportant femoro-poiiliteal branch, and enters the 

 tibio-peroneal arch to constitute the anterior tibial artery, after distributing on its course 

 muscular ramuscules — rudiments of the posterior tibial artery of other animals. 



The anterior tibial artery, arriving in front of the hock, detaches the tarsal artery — a 

 voluminous branch, divided near its origin into several superficial superior and inferior branches. 

 It continues to descend, traverses from before to behind the superior part of the third inter- 

 metatarsal space, and terminates by an arterial arch situated beneath the flexor tendons ; from 

 this arch emanate ascending divisions, that anastomose with the plantar arteries, and three 

 large descending or digital branches, which affect the same disposition as three analogous 

 principal arteries emanating from the superficial palmar arch of 

 the anterior limb. 



Fig. 374. 



Comparison of the External Iliacs of Man witk those of 

 Animals. 



In Man, the external iliac forms the external branch of the 

 bifurcation of the common iliac ; it extends to the crural arch, 

 where it takes the name of femoral artery. It furnishes the cir- 

 cumflexa ilii and epigastric : the latter resembling, in its distribu- 

 tion, the posterior abdominal branch given off by the prepubic 

 artery in the Horse. 



Tlie femoral artery has the same general disposition as in 

 animals, and almost the same collateral branches. There is no 

 prepubic artery ; the divisions furnished by this trunk in Solipeds 

 originate separately from the femoral artery ; these are : the 

 abdominal tegumental artery (superficial epigastric), and the exter- 

 nal pubic arteries — the one resembling the subcutaneous abdominal 

 artery, and the others the branches of the external pudic artery 

 of animals. 



The popliteal artery is a superficial vessel situated at the 

 posterior face of the knee-joint, in a lozenge-shaped space limited 

 by the muscles of tlie region, and named the popliteal space. At 

 the tibio-peroneal arch it bifurcates, and constitutes the anterior 

 til'ial and the tibio-peroneal trunks. 



The tibio-peroneal artery does not exist in animals in which 

 tlie peroneal artery is in a rudimentary state, in consequence of 

 the feeble development of the peroneus. This trunk is short, and 

 furnishes the nutrient artery of the tibia, then divides into the 1 

 peroneal and posterior tibial artfries. The first descends to the 

 external malleolus, along the inner f ice of the tibia, and terminates 

 in two branches, one of which, the anterior peroneal, communicates 

 with the dorsal artery of the tarsus — a branch of the pedal. The 

 posterior tibial, on reaching the concavity of the caleis, constitutes 

 the internal and external plantar arteries. The internal plantar 

 is directed forwards, beneath the sole of the foot, and is lost in the 

 muscles of the great toe, or forms the collateral of the latter vessel. 

 Beneath the tarsal articulations, the external plantar describes a 

 curve, having its concjtvity backwards, and anastomoses, at the 

 fourth intermetatarsal space, with the termination of the dorsalis 

 pedis; from this results a plantar arch, which gives off, from 

 without to within: 1. The external collateral of the little toe; 



2, 3, 4, 5, the interosseous plantar (or digital) arteries of the first, second, third and fourth 

 intermetatarsal spaces ; these arteries, at the root of the toes, bifurcate to furnish collaterals 

 to these organs. 



The anterior tibial artery, situated on the anterior face of the interosseous ligament that 

 unites the tibia to the peroneus, extends to the annular ligament of the tarsus, where it is con- 

 tinuerl by the dorsalis pedis, which descends along the dorsum of the foot to gain the summit 

 of the fourth interosseous space. 



The dorsal artery of the metatarsus (metatarsea) is almost nil in Solipeds. In Man it is 

 directed transversely to the tarsus, from within to without ; its terminal branches unite on the 

 dorsum of the tarsus, and the arch itWrns gives off the dorsal interosseous arteries of thetliree 

 first spaces. These communicate above and below, in the intermetatarsal spaces, with the 



arteries of sole of 

 human foot. 



, Under surface of os cal- 

 eis ; 2, musculus aoces- 

 sorius ; 3, long flexor 

 tendons ; 4, tendon of 

 peroneus longus ; 5, ter- 

 mination of posterior 

 tibial artery; 6, internal 

 plantar ; 7, external 

 plantar ; 8, plantar arch 

 giving oft' four digital 

 branches, three of which 

 are seen dividing into 

 collaterals for adjoining 



