DISSECTION OF THE DOG 77 



its medial side, and receives tributaries corresponding to the branches of the 

 artery. It assists the hypogastric vein in the formation of the common iliac 

 vein. 



A. SAPHENA, V. SAPHENA MAGNA, ET N. SAPHENtTS. — About the point at 



which the borders of the gracilis and sartorius muscles meet, three structures 

 make their appearance. These are the saphenous artery, vein, and nerve ; of 

 which the nerve is most oral and the vein most aboral. Running immediately 

 underneath the fascia, they are continued from the thigh into the leg. A branch 

 from each of the three passes across the medial aspect of the joint between the 

 femur and the tibia to supply the skin in this region. 



M. gracilis. — The oral part of the gracilis muscle is very thin, but its 

 aboral border is of considerable thickness. The origin of the muscle is mainly 

 from the tendon of the adductor of the thigh and from the gracilis muscle of the 

 opposite side. In addition a part of the muscle arises from the symphysis 

 ischii and the border of the ischium. The insertion is to the anterior tibial 

 crest by means of a broad, thin tendon blended with the tendons of the 

 sartorius and semitendinosus muscles. 



The main nerve of the gracilis (a branch of the obturator nerve) appears 

 between the pectineus and adductor muscles, crosses the surface of the latter, 

 and then enters the deep face of the gracilis. 



M. sartorius. — The sartorius muscle lies oral to the gracilis, and is clearly 

 divided into two parts : (1) The oral portion arises from the lateral angle of the 

 ilium, and is inserted into the patella by a flattened tendon partly blended with 

 the common insertion of the muscles of the front of the thigh ; (2) the aboral 

 portion has origin from the ventral border of the ilium. Its tendon partly 

 joins that of the gracilis, but is also partly attached to the medial surface 

 of the tibia. 



A. eemoralis. — The first part of the femoral artery lies in a triangular 

 space, the femoral triangh (trigonum femorale), bounded by the sartorius and 

 pectineus muscles and the inguinal ligament of Poupart. The branches which 

 arise from this part of the artery are : (1) The lateral circumflex artery ; (2) the 

 anterior femoral artery ; and (3) small muscular branches. The first and second 

 branches may leave the femoral artery either separately or in common. In any 

 case their origin only can be seen at present. Leaving the femoral artery just 

 as it crosses the border of the ilio-psoas muscle, they immediately disappear 

 under the aboral part of the sartorius muscle. 



Of the small muscular branches the largest arises close to the apex of the 

 femoral triangle and is mainly concerned in the supply of the gracilis. 



Dissection. — Reflect the gracilis and sartorius muscles by cutting across them 

 about the middle of their length. In turning upwards the proximal part 

 of the sartorius be careful to preserve the nerve to the muscle (ramus 

 anterior of the femoral nerve) and the lateral circumflex artery. 



