772 ARTERIES OF THE INFERIOR EXTREMITY. 



dense, fibrous membrane, situated between the skin and 

 muscles, attached to the tubercles of the os calcis, and 

 spreading over the whole sole of the foot. It is divided 

 into three portions, an outer, attached to the base of the 

 fifth metatarsal bone an inner connected to the metatar- 

 sus of the great toe; and a middle, much thicker and 

 denser, which, as it leaves the os calcis, expands, and, at 

 the heads of the metatarsal bones, divides into five fasciculi, 

 each of which again divides so as to form a slit for the 

 passage of the flexor tendons. These go to be inserted into 

 the sides of the basis of the first phalanges of the toes. 



SECTION III. 

 BLOOD-VESSELS OF THE INFERIOR EXTREMITY. 



The femoral and popliteal arteries, with their branches, 

 ,are the sources of arterial supply to the lower extremity. 



FEMORAL ARTERY. 



'The femoral artery is a continuation of the external iliac. 

 At about the centre of Poupart's ligament it commences, 

 and extends obliquely inward along the anterior thigh to 

 an opening in the adductor magnus muscle, through which 

 it passes, and changes its name to popliteal. 



In its course it first passes over the common junction of 

 the psoas magnus and iliacus internus, then over the ad- 

 ductors brevis and longus. Above it is rather superficial 

 and simply covered by a thin layer of the fascia lata ; at 

 the middle of the thigh the sartorius crosses it, and here is 

 also seen a strong covering of aponeurotic membrane from 

 the vastus internus, and adductor longus. At Poupart's 

 ligament the femoral vein is on the inside of the artery, 

 while as it descends the vein gets behind it. The anterior 

 crural nerve is to the outside, and one of the branches de- 

 scends along the front of the artery within the sheath. 



A line drawn from midway between the anterior supe- 

 rior spinous process of the ilium and symphysis pubis to 

 the inner sido of the patella, will indicate the course of this 

 vessel. 



