168 



ANATOMY AND PHYSIOLOGY OF 



vis, the urinary and genital organs, and the 

 posterior extremities. It takes its course 

 under the bodies of the lumbar vertebraB, 

 runs along the great fissure of the liver, 

 perforates the cordiform tendon, and pur- 

 sues its way directly across the cavity of 

 the chest to the lower part of the right auri- 

 cle : in its passage it is joined by the lum- 

 bar spermatic, renal, hepatic, and diaphragm- 

 atic veins. 



The common iliac veins are formed under 

 the sacro-iliac, symphysis, by the union of 

 the external and internal iliacs ; they re- 

 ceive a vein from the psoas and iliacus, cir- 

 cumflex vein of the ileum, middle sacral, 

 and azygos. 



The ischiatic vein, situated upon the side 

 of the pelvic cavity, midway between the 

 external iliac and lateral sacral veins ; ex- 

 ternal and internal branches unite to form 

 it. The internal comprise veins coming 

 from the bladder, anus, perineum, and, in 

 the male, from the bulb and prostate: in 

 the female, from the vulva and body of the 

 vagina. The external come principally 

 from the gluteal and obturator muscles. 



The lateral sacral vein comes from the 

 tail, formed by coccygeal veins ; it runs 

 forward to the sacrum, and receives in 

 its course the perineal and sacro-spinal 

 branches. 



The external iliac vein takes the same 

 course as the artery ; as it departs from the 

 belly, this vessel receives 



The inguinal vein (coming from the 

 groin), also a superficial or cutaneous 

 abdominal vein, known as the milk vein in 

 cattle. 



The femoral vein is the continuation of 

 the iliac trunk below the brim of the pelvis ; 

 and is the main channel into which the 

 deep-seated veins of the hind extremity 



pour their blood. We commence the de- 

 scription, as in the fore extremities, at the 

 leg. 



The large metatarsal vein ascends the 

 canon by the side of the flexor tendons, 

 and passes over the front and inner part of 

 the hock ; it sends out branches, from which 

 result the 



Anterior tibial veins, which run between 

 the tibia and fibula to the back and lower 

 part of the os femoris, and then are joined 

 by the posterior tibial vein, and all tlnree 

 unite to form the femoral. 



The posterior tibial vein is a continua- 

 tion of the small metatarsal vein, and cor- 

 responds in size to the small metacarpal. 

 It runs in company with the posterior tib- 

 ial artery, receiving various muscular 

 branches in its course, also the medullary 

 vein of the tibia. 



The femoral vein results from the two 

 last-named vessels ; runs behind the femoral 

 artery, and ends in the external iliac vein. 

 It receives muscular veins, as well as veins 

 from the stifle joint, and the medullary vein 

 of the OS femoris ; also, about two-thirds of 

 its length upwards, it is joined by the saph- 

 ena vein. 



The vena saphena major results from the 

 large metatarsal vein ; at the hock it anas- 

 tomoses with the anterior tibial vein; it 

 also receives cutaneous and muscular 

 branches in its course. 



The vena saphena minor springs from the 

 small metatarsal vein ; it runs up the back 

 of the hock, over the root of the os calcis, 

 and ultimately reaches the femoral vein. 



The vena porta circulates the blood 

 through the liver, and is principally formed 

 by the union of the splenic and mesenteric 

 veins. 



