336 SPECIAL ANATOMY. 



587. The vascular arches of the foot. 



1. Arcus dorsalis pedis s. tarseus dorsalis, close upon the dorsal surface of 

 the metatarsal bone, is before convex, and arises from the junction of the 



Art. metatarsea with the anterior branch of the art. tarsea. 

 From it three branches arise : 



Arlt. interossecB dorsalis pass in the second to the fourth interstitium in- 

 terosseum metatarsi, where they give off the three : 

 Artt. perforantes, which sinks downwards, and pass opposite to the 

 artt. perforantes from the arcus plantaris; 



whilst they divide in a forked manner at the anterior extremity into the 

 small : 



Artt. digitales dorsales, which betake themselves to the dorsal sur- 

 face of the toes, from the external border of the second as far as the 

 internal of the fifth toe, terminate on the first phalanx, and unite 

 with the corresponding of arcus plantaris. 



Both borders of the first and the internal border of the second toe are 

 supplied from art. dorsalis hallucis, the terminal branch of art. pedicea. 



2. Arcus plantaris (profundus, there is no arcus plant, sublimis present), 

 close under the posterior extremities of the metatarsal bones in the sole of the 

 foot, is convex before, and arises principally from the junction of: 



Art. plantaris externa with art. pediced (also tibial. postica and anticd). 

 From it three superior and five anterior branches arise : 



a. Artt. perforantes (three) ascend (see arc. dorsalis). 



b. Artt. interossea, four, pass in the second to the fourth interstit. in- 

 teross., divide at the anterior extremity into two branches: 



Artt. digitales plantares, which supply the outer border of the great, 

 the inner of the fifth toe, and both plantar borders of the second, 

 third, and fourth toes, and unite in an arch on the ungual phalanx. 



588. The Veins of the great Circulation. 



They form, with the exception of the two .veins of the heart, two 

 principal trunks, namely, V. cava superior, which carries the 

 blood from the superior, and V. cava inferior, which carries it from 

 the inferior half of the body to the right auricle of the heart. Both 

 stand in relation by means of a lateral branch, V. azygos, which 

 arises in the inferior half of the body and opens into the superior 

 vena cava. With the system of the inferior cava an important one 

 is included, the system of the Portal vein, and in the fetus the um- 

 bilical vein, besides. 



589. A. Vence cordis s. cardiaca. 



1. V. coronaria magna cordis. Course : from the apex of the heart as far as 



