THE ARTERIES. 313 



anterior and passes distad along the dorsal (anterior) border 

 of the fibula. 



Branches of the popliteal artery : 



1. A. suralis. This is a large branch which passes distad 

 from the caudal side of the popliteal artery. It sends branches 

 to the biceps and to the fat in the popliteal space, and passes 

 onto the ventral border of the lateral head of the gastrocnemius. 

 It sends branches to both heads of the gastrocnemius and to 

 the popliteus, passes distad onto the lateral surface of the ten- 

 don of Achilles, and may be traced to the proximal portion of 

 the dorsolateral side of the foot, where it sends many branches 

 to the integument about the ankle-joint. It then passes along 

 the lateral side of the foot and supplies the artery on the lateral 

 side of the fifth digit. 



2. Aa. genu posteriores. Several small arteries which 

 pass to the knee-joint. 



3. Rami musculares. Numerous small branches to the 

 muscles about the popliteal space. 



4. A. tibialis posterior. This is the largest branch of the 

 popliteal artery, which it leaves just before the latter passes 

 beneath the popliteal muscle. The tibialis posterior passes at 

 first mediad, then turns distad, passes across the popliteus 

 muscle onto the surface of the flexor longus hallucis, and 

 ramifies in the substance of this muscle and its tendon. It 

 gives branches also to the gastrocnemius and soleus. (It does 

 not pass into the foot as does the corresponding artery in 

 man.) 



5. A. tibialis anterior. The anterior tibial artery is the 

 continuation of the popliteal after its passage through the inter- 

 osseous membrane between tibia and fibula to the dorsal side of 

 the lower leg. Here it passes distad, lying against the inter- 

 osseous membrane, between the extensor longus digitorum and 

 the tibialis anterior muscle, or partly imbedded in the substance 

 of the latter. It passes, lying beneath the tendons of these 

 muscles, through the transverse ligament proximad of the 

 malleoli, thus reaching the dorsum of the foot. It extends dis- 

 tad across the tarsus to the space between the second and third 

 metatarsals, and through this space to the plantar side of the 



