Chap.X.] 



THE HEART AND CIRCULATION. 



Each is formed by the union of three factors, external jugular 

 (ex. ju.) from the jaw and tongue, innominate (in.), and sub- 

 clavian (s. d. v.). The innominate has two factors, internal 

 jugular (in.ju.) from the brain, etc., and subscapular (s. sc.) from 

 the region of the shoulder. The subclavian has also two factors, 

 the brachial (br.) from the fore-arm and manus, and the great 

 cutaneous (m. c.) chiefly from the skin of the back. 



Fig. 61 shows diagrammatically the arrangement of the 

 vessels in the pelvic region, seen from the ventral aspect. The 

 dorsal aorta (d. ao.) gives off vessels to the kidneys (one side 

 shown), and then bifurcates into 

 two iliac arteries (il.\ which, 

 after giving off a hypogastric 

 branch (liy.) to the bladder and 

 abdominal walls, continues on to 

 supply the leg. From the leg 

 the blood is returned by two 

 veins, the femoral running down 

 the front of the thigh, and the 

 sciatic running alongside the 

 artery in the back of the 

 thigh. These two are united by 

 an anastomosing branch (a. b.). 

 The femoral then branches into 

 two, the pelvic vein (pe.\ and the 

 renal portal (r. p.\ into which the 



Sciatic also falls. The pelvic a - b - Anastomosing branch between 



. , , . , , sciatic, and femoral veins, an. ab. An- 



Veins, On either Side, pass towards terior abdominal vein. d. ao. Dorsal 



the ventral aspect, and unite to aorta - d - l Dorso-iumbar vein. fe. v. 



P . , i i i Femoral vein. hy. Hypogastric artery. 



form the anterior abdominal vein, ilt Iliac artery- pe . Pelvic vein . 



which, as We have Seen, passes P f - c - Postcavalvein. re. a. Renal artery. 

 ,1 -i . mi , . i re. v. Renal vein. r. p. Renal-portal vein. 



to the liver. The renal-portal sc> Vm Sciatic vein> 



passes to the outer edge of the 



kidney, and breaks up into a capillary plexus in that organ. 



It receives a dorso-lumbar vein from the spinal canal and the 



body-wall. 



Let us now see, with the aid of Fig. 62, I. n. m., how the 



Fio. 61. RENAL-PORTAL AND PELVIC 

 VESSELS : FROG. 



