Beside those branches, which have been enumerated, to which proper names have been given, the profunda artery gives off during its course others less regular and less considerable, which are distributed to the muscles in its vicinity. Those are a branch to the pectinalis and adductor muscles, and one or more to the vastus internus and crurwus muscles : it has been elsewhere stated that the descending branches of the external circumflex, destined to the last-named muscles, and one of those to the vastus externus, at times also arise from the profunda itself. After having given off the last perforating artery, the profunda, very much reduced in size, continues its descent behind the adductor longus muscle, inclining at the same time outward, and external to the femoral artery : it passes through the adductor magnus a little above the passage of the femoral into the ham, giving it small branches; then tra verses the origin of the short head of the biceps, giving it also branches; and, lastly, enters into the outer part of the vastus externus, through which it descends frequently to near the knee, distributing branches to the muscle, and anasto musing with the descending branches of the external circumflex and with the external arti cular artery. The termination of the profunda is by some called the fourth perforating artery.
The profunda resembles very much in its course and termination the superior profunda or musculo-spiral branch of the brachial artery, to which it may be considered analogous.
Immediately before the femoral artery passes into the popliteal space, it gives off its fifth and lowest branch. This is usually called the anastomoika magna artery, but there being no more reason to apply the epithet anastomotic to it than to the other branches of the femora, and the great anastomotic artery of the thigh being in reality the profunda, the name given to it by Tiedemann seems much to be preferred, viz. superficial superior internal articular. It arises from the front of the femoral at the inferior part of its last stage, and immediately escapes from within the femoral canal, passing through its anterior wall at the same time with the saphenus nerve, as the femoral itself is about to pass into the ham. Having come through the aponeurosis forming the wall of the canal, it descends for some distance toward the inside of the knee parallel to the tendon of the adductor magnus and anterior to it in company with the saphenus nerve, and covered by the sartorius muscle. After a short course it divides into two branches. One of these runs down ward and forward, in front of the adductor magnus, toward the patella; enters the vastus internus and traverses it in its course ; divides within it into two branches, of which one runs between the muscle and the bone, and supplies the periosteum of the femur and the capsule of the articulation, anastomosing at the same time with the deep articulars ; the other continues its course through the vastus, supplying the muscle, until it reaches the side of the tendon of the extensors : it then becomes superficial to the tendon, and descends upon the front of the patella, ramifying freely upon it, supplies the integuments and other superficial structures of the articulation on its anterior part, and com municates freely with the other articular arte ries.
The second branch, into which the superfi cial articular divides, descends posterior to the tendon of the adductor, in company with the saphenus nerve, and covered by the sartorius : as it descends, it gives branches to the ham string muscles, the semi-membmnosus and semi tendinosus, and also to the sartorius : when it has reached the inner side ofthe knee, it divides into two, of which one passes forward beneath the aponeurosis, upon the internal condyle of the femur, divides into branches which supply the superficial structures of the joint upon its inside, can be traced forward beneath the pa tella, and form free communications with the other articular arteries, more particularly with the inferior internal one: the second descends to the leg, escapes from beneath the tendon of the sartorius, and then, turning forward, rami fies over the internal surface of the tibia below its tubercle, supplies the insertions of the mus cles and the coverings, and communicates with branches of the internal articular and of the tibial recurrent arteries. The superficial supe rior internal articular artery is variable in size : at times it is of very considerable magnitude ; at others it is small, or even absent altogether, its place being supplied by a branch of the popliteal artery. Its distribution also varies with its size, the extent of the former being proportioned to the latter.
The course of the artery diverges but little from that of the femoral, and the relation of the saphenus nerve to it is almost the same as that which the nerve holds to the latter vessel : hence, when the branch is large, it is liable to be mistaken in the operation of tying the main vessel, particularly in case of wound of the artery, for the femoral itself. The description of the articular artery here given has been taken from the plate of Tiedemann, in which the vessel is represented with its most extended distribution.
The femoral artery also gives off, during its descent through the thigh, beside the branches which have been described, several others to the muscles which are in its vicinity ; above, it sends branches to the sartorius, iliacus, and pectinalts ; and in the middle of the thigh to the vastus internus on the one hand, and to the adductor muscles on the other. Those branches are for the most part inconsiderable in size, and have not received names, but they are de serving of attention, inasmuch as they coope rate in the collateral circulation, more particu larly the second set, through which the femoral artery is generally preserved pervious, after ligature below the origin of the profunda, during a greater or less extent of the interval between the ligature and the popliteal artery, by means of the anastomoses between the branches in question and the circumflex arteries.