106 ANATOMY IN A NUTSHELL. 



are on the back of the forearm, and Extensor carpi radialis brevior in the radial 

 region. 



The internal cutaneous nerve comes from the inner cord and its fibers may 

 be traced to the eighth cervical and first dorsal nerves. The cutaneous branch 

 perforates the deep fascia in the axilla to supply integument over the back of 

 the arm nearly to the elbow. About half way along the inner side of the arm 

 it pierces the deep fascia with the basilic vein, dividing into anterior and pos- 

 terior branches. The anterior branch passes to the forearm either in front of, 

 or behind the median basilic vein, supplies integument of the ulnar aspect of the 

 anterior surface of the forearm as far as the wrist and communicates with the 

 ulnar. The posterior branch passes in front of the internal condyle to the 

 forearm where it supplies integument on the ulnar aspect of the dorsum of the 

 forearm as far as the wrist. Above the elbow it anastomoses with the lesser 

 internal cutaneous and at the wrist with the dorsal cutaneous of the ulnar. 



The lesser internal cutaneous (nerve of Wrisberg) is the smallest branch of 

 the brachial plexus. It comes from the inner cord and its fibers are traced to 

 the first dorsal and sometimes the eight cervical in addition. In the axilla it 

 communicates with the intercosto-humeral forming one or two loops. It is sit- 

 uated on the inner side of the axillary often being separated from the vein by 

 the ulnar nerve. About the middle of the arm it pierces the dee]> fascia supply- 

 ing integument over the olecranon. 



LESSON XXVII. 



The hand.— (Plates XXVI-XXVII.) — There are twenty-seven bones in 

 the hand while there are but twenty-six in the foot, there being one more bone 

 in the carpus (wrist ) than in the tarsus (ankle.) The number of muscles in the 

 hand is twenty, the same as in the foot. There are also twenty muscles in the 

 forearm. In the thumb (thenar eminence) there are five muscles, viz., Ab- 

 ductor pollicis, < >pponens pollicis ( Flexorossis metacarpi pollicis.) Flexor brevis 

 pollicis, Adductor obliquus pollicis, and Adductor transversus pollicis. The first 

 two gel the median nerve, the third one gets both the median and the ulnar 

 nerves, while the last two get the ulnar. On the ulnar side of the hand there is 

 the Palmaris brevis and the three muscles of the little finger (hypothenar emi- 

 nence!, viz.. A lull ict or minimi digit i. Flexor brevis minimi digiti, and theOpponens 

 minimi digiti (Flexor ossis metacarpi minimi digiti). All these are supplied by 

 the ulnar nerve. In the middle palmar legion there are four Lumbricales, f our 

 Dorsal interossei, and three Palmar interossei. The two outer Lumbricales are 

 supplied by the median nerve, and the two inner ones and the seven Interossei 

 by the ulnar nerve. The bones in the carpus are in two rows, those of the first 

 row. beginning on the radial side are the scaphoid, semilunar, cuneiform, and 

 pisiform, and those in the second row beginning on the radial side are the trape- 

 zium, trapezoid, os magnum, and unciform. The five beyond the carpus are 

 called the metacarpals, and the fourteen in the fingers and thumb are the phal- 

 langes. Then the eighl carpal, plus the five metacarpal, plus the fourteen 

 phalanges, make the twenty-seven bones of the hand. 



