Veins of the Upper Fig. 144 shows the surface veins of the hand and forearm, uniting to form three main trunks, 3, the radial vein, which begins on the back of the hand, 7, the median vein, formed by the union of small vessels of the palm of the hand, and 5, the ulnar vein, which commences en the inner side of the back of the hand and receives a large branch from the front of the forearm. These vessels form a peculiar arrangement at the elbow, shown in Fig. 144, the median vein, at 6, giving off a branch at one side to the vsin marked 4, the basilic vein, and a branch /A the other side to the cephalic vein, marked 1. It is the branch between 6 and 5 that is usually opened in the operation of bleeding at the arm. The two large veins, cephalic and basilic, pass up the arm. The latter, which in the figure is represented as disappearing a little above the elbow, courses up the inner side of the arm a little more deeply than it is at the elbow, and passes through the arm-pit, being then called the axillary vein, over the margin of the first rib and so behind the collar bone. Here it is called the subclavian vein, and its farther course has been al ready noticed. The cephalic vein joins the axillary.
Besides the veins named there are veins deeply placed in the substance of the upper limb, accompanying the branches of arteries. These all in the end join the axillary vein. Thus this one large vessel carries from the arm all the blood brought to it by arteries.
Veins of the Lower 145 shows the surface veins of the inner side of the leg and foot.
One large vein is there seen.
Beginning in branches from the inner side of the foot it passes up the inner side of the ankle to the inner side of the knee and thence to the front of the thigh, where at 1 it dips inwards to end in a vein lying alongside of the femoral artery (p. 307). This is the internal or long saphenous vein. Over the outer ankle and outer side of the leg the short saphenous vein runs, but only to the ham, into which it pene trates to join a deep vein.
Deep veins in the lower limb accompany the arteries, the course of some of which has been noted (p. 307). The femoral vein, which lies side by side with the femoral artery, passes through the groin into the cavity of the belly to end in the external iliac vein, lying along side the artery of the same name. This vein, carrying all the blood from the lower limb, is joined by the internal iliac vein, bringing blood from the buttocks and pelvic organs and cavity. Together they form the common iliac vein. The common iliac veins, one from each side of the body, unite near the lower end of the back bone to form the inferior vena cava, which passes upwards in the cavity of the belly, re ceiving additions from the organs there, from liver, kidneys, &c., pierces the diaphragm, and enters the right side of the heart.
Thus the inferior vena cava brings all the blood from the lower limbs and belly to the right side of the heart, as the superior vena cava performs a like office for the upper part of the body.