| OCR Text |
Show 1894.] ANATOMY OF ATHERURA AFRICANA. 691 tendon of the psoas parvus ; it supplies the skin of the outer side of the thigh. The anterior crural nerve rises from the 3rd and 4th L. and emerges from the front of the psoas beneath Poupart's ligament; it then gives off a large cutaneous branch, which soon divides into anterior and posterior branches to supply the inner side of the leg ; the anterior branch supplies the skin of the front of the inner side of the thigh and leg as far as the dorsum of the foot. In company with this cutaneous branch, from the superficial surface of the anterior crural, a branch is given off to the pectineus, which enters it on its deep surface. The rest of the anterior crural supplies the quadriceps, but does not supply the sartorius. There is no long saphenous nerve apart from the cutaneous branch already described. The obturator nerve rises from the 3rd and 4th L. and emerges from the inner side of the psoas; it pierces the obturator membrane supplying the obturator externus, after which it divides into branches for the pectineus, adductors, and graciles. There is no accessory obturator. The sacral plexus is formed by the 5th L. and the 1st and 2nd S., joined by a branch from the obturator. From the cord formed by the last L. and the branch of the obturator, a nerve is given off to supply the sartorius, tensor vaginae femoris, and gluteus maximus, while close by twigs are given off to the other gluteals and short external rotator muscles. The nerve to the hamstrings is nearly as large as the great sciatic; it is derived from the 5th L. and 1st S. The great sciatic comes from the whole of the plexus, but the twig from the 2nd S. is very small. It runs down the back of the thigh as in M a n , and gives off a cutaneous branch corresponding to the small sciatic. It divides into external and internal popliteal in the lower third of the thigh. The external popliteal gives off a branch corresponding to the communicans fibularis of human anatomy, which pierces the biceps to supply the skin of the back and outer side of the leg; after this it divides into musculocutaneous, anterior tibial, the nerves to the peronei and nerves to the extensor muscles of the leg. The musculo-cutaneous runs doAvn to the dorsum of the foot. The anterior tibial supplies the extensor brevis digitorum and the skin of tbe contiguous sides of the 2nd and 3rd and 3rd and 4th toes. The internal plantar nerve gives off the short saphenous nerve to the back of the leg and outer side of the foot, after which it runs down the leg as the posterior tibial, supplying the superficial and deep muscles of the calf. At the ankle it divides into the external and internal plantars, which, in their distribution, correspond to the ulnar and median nerves of the hand. The external plantar supplies all the muscles of the sole except the flexor brevis digitorum and abductor hallucis, but gives off no cutaneous branch. The internal plantar supplies these two muscles and the skin of all the toes on their |
