682 SYNOPSIS OF CUTANEOUS NERVES. 



ANTERIOR TIBIAL NERVE. 



The anterior tibial (interosseous nerve), commencimg between the fibula 

 and the ]:eroneus longus, inclines obliquely beneath the long extensor of 

 the toes to the fore part of the interosseous membrane, and there comes 

 into contact with the anterior tibial vessels, and with those vessels it 

 descends to the front of the ankle-joint, where it divides into an external 

 and an internal branch. The nerve first reaches the outer side of the 

 anterior tibial artery, above the middle of the leg ; and, after crossing in 

 front of that vessel once or oftener, lies to the inner side of it at the bend 

 of the ankle. 



(a) Muscular branches. In its course along the leg, the anterior tibial nerve 

 gives slender filaments to the muscles between which it is placed, namely, the tibialis 

 anticus, the long extensor of the toes, and the special extensor of the great toe. 



(b) The external branch of the anterior tibial nerve turns outwards over the tarsus 

 beneath the short extensor of the toes ; and, having become enlarged (like the pos- 

 terior interosseous nerve on the wrist) terminates in branches which supply the short 

 extensor muscle, and likewise the articulations of the foot. 



(c) The internal branch, continuing onwards in the direction of the anterior tibial 

 nerve, accompanies the dorsal artery of the foot to the first interosseous space, and 

 ends in two branches, which supply the integument on the neighbouring sides of the 

 great toe and the second toe on their dorsal aspect. It communicates with the inter- 

 nal division of the musculo-cutaneous nerve. 



Summary of the external popliteal nerve. This nerve supplies, besides 

 articular branches to the knee, ankle, and foot, the peronei muscles, extensor 

 muscles of the foot, also the integument of the front of the leg and dorsum 

 of the foot. It gives the ramus communicans fibularis to the short 

 saphenous branch of the internal popliteal nerve, and communicates with 

 the long saphenous nerve. 



SYNOPSIS OF THE CUTANEOUS DISTRIBUTION OF THE 

 CEREBRO-SPiNAL NERVES. 



HEAD. The face and head in front of the ear are supplied with sensory 

 nerves from the fifth cranial nerve. The ophthalmic division supplies 

 branches to the forehead, upper eyelid, and dorsum of the nose. The 

 superior maxillary division supplies the cheek, ala of the nose, upper lip, 

 lower eyelid, and the region behind the eye, over the temporal fascia. The 

 inferior maxillary division supplies the chin and lower lip, the pinna of the 

 ear on its outer side, and the integument in front of the ear and upwards to 

 the vertex of the head. 



The head, behind the ear, is mainly supplied by the great occipital branch 

 of the posterior division of the second spinal nerve, but above the occipital 

 protuberance there is also distributed the branch from the posterior division of 

 the third spinal nerve ; and, rn front of the area of the great occipital nerve, is 

 a space supplied by anterior divisions of spinal nerves, viz., the back of the 

 pinna of the ear, together with the integument behind and that in front over 

 the parotid gland, which are supplied by the great auricular nerve ; while 

 between the area of that nerve and the great occipital the small occipital 

 nerve intervenes. The auricular branch of the pneumo-gastric nerve also 

 is distributed on the back of the ear. 



TRUNK. The posterior divisions of the spinal nerves supply an area, 

 extending on the back from the vertex of the skull to the buttock. This 

 area is narrow in the neck ; it is spread out over the back of the scapula ; 



