REGIONS OF THE FOOT. 



355 



so divides into external and internal plantar. 

 The first of these, which is much the larger 

 of the two, runs in a somewhat semicircular 

 course, first forwards and outwards till it has 

 reached the base of the metatarsal bone of the 

 little toe, and then winds round across the 

 other metatarsal bones, till at that of the great 

 toe it terminates by uniting with the anterior 

 tibial. In this course it runs first between the 

 superficial and deep muscles, viz. first covered 

 by the abductor pollicis, then between the 

 flexor brevis digitorum and the long flexor 

 tendons ; it then becomes more superficial, 

 King between the flexor digitorum brevis and 

 the abductor minimi digiti ; then in crossing 

 back to the inner side of the foot, it runs deep 

 under all the muscles and tendons, except the 

 interossei. Thus this artery forms an arch, 

 called the plantar arch, having its convexity 

 forwards and outwards, its concavity inwards 

 and backwards. The branches which it sup- 

 plies in this course are, first, a number of large 

 muscular branches before it reaches the outer 

 side of the foot ; then from the convexity of 

 the arch itself, the digital arteries, one to each 

 metatarsal space, which, dividing at the first 

 joint of the toes, run one on each side of the 

 toe to its termination ; and lastly, those from 

 the upper and inner sides, being generally very 

 insignificant muscular branches and communi- 

 cating branches, these last going upwards 

 between the metatarsal bones to anastomose 

 with the metatarsal branches of the anterior 

 tibial artery. It is right, however, to state 

 that in this, as in every other part of the 

 arterial system, great variety is occasionally 

 found. The internal plantar artery is a com- 

 paratively small artery, merely going to supply 

 the muscles and integuments of the great toe, 

 and for this purpose passes forwards along the 

 under and inner side of the tarsus, covered by 

 the abductor pollicis as far as the first phalanx 

 of the great toe, where it divides into several 

 branches, supplying both sides of the great toe, 

 and the inner side of the second. The veins 

 which accompany the plantar arteries are, like 

 all deep-seated veins, two in number, one on 

 each side of the artery, and they terminate in 

 the hollow of the os calcis by forming the 

 posterior tibial veins. The plantar arteries are 

 accompanied also in their course by corre- 

 sponding nerves, the termination of the poste- 

 rior tibial nerve, which divides in the hollow 

 of the os calcis. The internal plantar nerve, 

 contrary to the order of the arteries, is the 

 larger of the two ; it runs in company with the 

 inner plantar artery, and sends branches to the 

 three inner toes, and to the inner side of the 

 fourth, while the external plantar nerve running 

 the course of the corresponding artery is dis- 

 tributed only to the fifth toe and outer side of 

 the fourth. The lymphatics of the sole of 

 the foot, like the rest of this system, are com- 

 posed of a superficial and a deep set, the 

 former collecting from all parts towards the 

 inner ankle; the latter accompanying the plan- 

 tar arteries and veins, and passing up also with 

 them behind the inner ankle, go with the tibial 

 veins to the ham. There are several synovial 



bursae in this region which it is necessary here 

 to mention. They are surrounding the tendons 

 as they pass into the sole along the hollow of 

 the os calcis, viz. the flexor longus pollicis and 

 flexor longus digitorum. Their anatomical 

 description has been already given (see ANKLE, 

 REGION OF). Another synovial sheath is 

 surrounding the tendon of the peroneus longus 

 as it obliquely crosses the sole to its insertion. 

 This bursal cavity is situated close upon the 

 bone, and under the principal ligaments. 



II. Plantar region of the toes. Of the 

 toes we observe that the integuments of the 

 under part are always soft and pliable, com- 

 pared with the rest of the integument of the 

 sole, and possessing peculiarly the sense of 

 touch ; that under the skin at the extremity 

 of the toes there is a soft elastic cushion of 

 cellular tissue, analogous to that at the tip of 

 the fingers, and in this and in the cutis the 

 extremity of the digital arteries and nerves is 

 minutely ramified. The digital arteries them- 

 selves, with their accompanying nerves and 

 veins and absorbents, are running along the 

 edges of this under surface of the toes. 

 Lastly, the tendinous thecae, in which the 

 flexor tendons are lying, are situated along 

 the under surface of the phalanges of the 

 toes, and are particularly attached to the sharp 

 edges of these bones (see FOOT, JOINTS 

 OF). They have a smooth synovial lining 

 which prevents the effects of friction upon the 

 tendons, and facilitates their movements. 



From the description which has now been 

 given of the organization of the plantar region 

 of the foot, we readily perceive, 1st, Why 

 deep wounds of this part are both followed by 

 considerable haemorrhage, and why this is at 

 the same time very difficult to stop. The 

 arterial branches are numerous and lie deep. 

 Before we can get at them either to press upon 

 or to tie them, we must do so through a thick 

 integument, a dense tendinous fascia, and 

 deep-seated layer of muscles. If we dilate 

 the opening in all these parts we wound many 

 more branches, while it is impossible at such a 

 depth, and through such part, to discover the 

 bleeding vessel, if the opening is small. We 

 are, therefore, compelled in such a case, if 

 pressure will not stop the haemorrhage, to tie the 

 posterior tibia! artery, either behind the ankle^ 

 or at the lower third of the leg. But even this 

 is sometimes not sufficient to stop the haemor- 

 rhage, owing to the free anastomosis of the 

 arteria dorsalis pedis with the plantar arteries ; 

 and we are then compelled also to tie the 

 anterior tibial. 2d, We see why inflammation 

 and suppuration in these parts, whose parietes 

 as well as contents are in great measure ten- 

 dinous, are threatening both in their present 

 symptoms and in their consequences. Not 

 only is the ready detection of suppuration pre- 

 vented, but the efforts of nature to bring it to 

 the surface are resisted. The inflamed parts 

 are bound tight; if matter has formed, it is 

 obliged to burrow laterally, in contact with 

 nerves, arteries, tendons, &c. The inflamma- 

 tion spreading to the synovial sheaths either 

 impairs or destroys the movements of the 

 2 A 2 



