I)ISTI>'l/irTI<>.\ <)! Till; CUTANEOUS 



995 



The front of tlic hand is supplied by the sixth, -eventh. and eighth cervical nerves 

 and by the first thoracic nerve through the superlicial radial (radial) nerve, and 

 through the median and ulnar nerves. The superficial radial supplies the radial side 

 of the thumb by its palmar cutaneous branch. The remainder of the palm and the 

 palmar aspects of the finders are supplied by the median and ulnar nerves through 

 their palmar cutaneous and digital brandies, the median supplying three and a half 

 digits and the ulnar the remaining one and a half (fig. 710). 



The dorsal aspect of the hand is supplied by the sixth, seventh, and eighth cervical 

 nerves, \\hich reach it through the superficial radial (radial) and through the median 



Fio. 712. DIAGRAM OF Tin: Ci IVNEOTS AHF.AS OF THE UPPER EXTREMITY. 



(After Thorburn.) 



and ulnar nerves. The superficial radial supplies the outer part of the dorsum and the 

 outer three and a half digits, except the lower portions of the second, third, and half 

 of the fourth digits, which receive twigs from the median nerve; the ulnar nerve 

 supplies the ulnar half of the dorsum of the hand, including the inner one and a half 

 digits. The areas supplied by definite spinal nerves, according to the observations of 

 Head and Thorburn, are shown in figures 711 and 712 respectively. 



THE CUTANEOUS AREAS OF. THE LOWER EXTREMITY 



There are six cutaneous areas in the region of the buttock, three upper and three 

 lower. Of the upper areas the outer is supplied by the anterior primary divisions 

 of the last thoracic and first lumbar nerves through the iliac branches of the last 

 thoracic and the ilio-hypogastric nerves; the middle upper area receives the lateral 

 divisions of the posterior primary branches of the upper three lumbar nerves, and the 

 inner upper area is supplied by twigs from the lateral branches of the posterior 

 primary divisions of the upper two or three sacral nerves (fig. 710). 



Of the lower three areas, the outer receives filaments from the second and third 

 lumbar nerves through the lateral femoral cutaneous (external cutaneous) branch of 

 the lumbar plexus; the middle area is supplied by the first, second, and third sacral 

 nerves through the posterior femoral cutaneous (small sciatic) nerve; and the inner 

 area by the second and third sacral nerves through the medial inferior clunial (per- 

 forating cutaneous) branch of the sacral plexus (fig. 710). 



On the back of the thigh there are three areas. The inner and the outer are 

 supplied by the second and third lumbar nerves, the former through the lateral 

 femoral cutaneous (external cutaneous) branch of the lumbar plexus, and the latter 

 through the anterior cutaneous branches of the femoral (internal cutaneous branch 

 of the anterior crural) nerve. The middle area receives twigs from the first, 

 second, and third sacral nerves through the posterior femoral cutaneous (small 

 sciatic), a branch of the sacral plexus. 



The front of the thigh is supplied by the first, second, and third lumbar nerves, 

 and then; are five cutaneous areas. The outer area receives twigs of the second and 

 third lumbar nerves through the lateral (external) cutaneous nerve. There are 



