The internal long saphenous vein is mistaken frequently for the femoral artery. It is a superficial vein and is usually found empty after death. It lies a short distance to the inner side of the femoral artery in Scarpa's triangle. This vein is taken up frequently, not only by the younger members of the profession, but by the older as well, when the guides are not followed closely, and when this mistake does occur, and fluid is injected through it, flushing of the face results.
Next to the common carotid artery the femoral artery is the largest branch artery used in embalming. The femoral artery commences immediately behind Poupart's ligament and is a continuation of the external iliac artery.
Fig. 50—The femoral artery. (Gray)
It passes down the forepart and inner side of the thigh, terminates at the opening in the adductor magnus, at the junction of the middle with the lower third of the thigh, where it becomes the popliteal artery. In the upper third the artery is contained in a triangular space called Scarpa's triangle and in the middle third of the thigh it is contained in an aponeurotic canal called Hunter's canal.
At a point about one and one-half to two inches below Poupart's ligament, the femoral artery gives off a branch to the outer and under side, known as the deep femoral artery, or the profunda femoris, which courses the thigh downward, and connects with branches coming off the popliteal and the anterior tibial arteries, thus forming the collateral circulation to the lower leg and foot.
As the femoral artery leaves the body, it is accompanied by the femoral vein, which for two inches down, lies along side the femoral artery to the inner and under side. At about this juncture, however, it passes underneath the artery and continues its course in that position until it passes below where we have occasion to use the artery.
The femoral artery can be used all the way from where it leaves the body at Poupart's ligament until it reaches Hunter's canal. At Poupart's ligament the artery is very superficial, being covered only by the skin, superficial fascia and superficial lymphatic glands, but it gets deeper further down, being covered not only by the above named tissues, but also by muscles, making it very difficult to raise in the middle and lower thirds of the thigh. About five to seven inches below Poupart's ligament the artery passes under the adductor magnus muscle, and enters what is known as Hunter's canal. Because this artery does get deeper as it courses down the thigh, it is generally raised in the upper third.
A knowledge of the anatomy of the vessels of the thigh and leg will be of value in treating accidents when this member is injured.