980 



THE VASCULAR SYSTEM. 



As it runs proximally, in the 

 the volar and dorsal aspects and, 



Brachialis 

 muscle 



Biceps muscle 

 Cephalic vein 



Radial 



recurrent artery 

 Lateral 



cutaneous nerve 

 of forearm 



Median cephalic 

 vein 



Accessory 

 radial vein 



Brachio-radialis 

 muscle 



Radial arte 



Median A r ei 

 of forearm 



Cephalic vei 



Fia. 791. SUPERFICIAL VEINS AT THE BEND OF THE ELBOW. 



arm it is either the median cubital 

 which is opened. 



forearm, it is joined by tributaries from both 

 in the cubital region, by the median cubital 

 vein which connects it 

 with the cephalic vein. 

 The Median Vein of 

 the Forearm. In a cer- 

 tain number of cases a 

 vein, which commences 

 in the palmar venous 

 plexus, runs along the 

 middle of the volar 

 aspect of the forearm to 

 the cubital region. It is 

 called the median vein 

 of the forearm. At the 

 bend of the elbow it 

 receives the profunda 

 vein and then divides 

 into two branches, the 

 median cephalic and the 

 median basilic veins 

 (Fig. 791). The median 

 * cephalic vein runs along 

 the lateral bicipital 

 sulcus and joins the 

 cephalic vein. The 

 median basilic passes 

 along the medial bi- 

 cipital sulcus and joins 

 the basilic vein. When 

 the median vein of the 

 forearm is present the 

 median cubital vein is 

 absent. 



When venesection 

 is performed in the fore- 

 vein or, in its absence, the median basilic vein 



silic vein 



Medial 

 utaneous 

 nerve of forearm 



-Basilic vein 

 Median nerve 



Brachialis 

 muscle 

 Brachial 

 artery 



edian basilic 

 vein 



Lacertus 

 h'brosus 



vein 

 Inar artery 



Profunda 

 vein 



Pronator teres 

 muscle 



VENA CAVA INFERIOR AND ITS TRIBUTARIES. 



The inferior vena cava (Fig. 792) is a large venous trunk which receives the 

 whole of the blood from the lower extremities, and the greater part of the blood 

 from the walls and contents of the abdomen and pelvis. It commences opposite 

 the right side of the body of the fifth lumbar vertebra, behind and to the right of 

 the right common iliac artery. It ascends through the abdomen, anterior and to the 

 right of the vertebral column and the right crus of the diaphragm, and it pierces 

 the cupola of the diaphragm, between the middle and right sections of the central 

 tendinous leaflet, at the level of the lower part of the eighth thoracic vertebra. It 

 then enters the middle mediastinum, pierces the fibrous pericardium, and terminates 

 in the lower and posterior part of the right atrium. Its intra-thoracic portion is 

 very short, and its intra-pericardial portion, which is still shorter, is covered 

 anteriorly and on its right and left sides by the parietal portion of the serous layer. 

 Attached to the inferior and anterior margin of its atrial orifice is the valve of 

 the inferior vena cava (Eustachian). This is a remnant of an important fold of 

 endocardium by which, in the foetus, the blood from the inferior vena cava is 

 directed, through the foramen ovale, into the left atrium. 



Relations. The inferior vena cava is in relation, posteriorly, with the bodies of the 



