162 SPECIAL ANATOMY. 



brachialia and nerv. medianus, forming on the inner side, below 

 the centre of the upper arm a semilunar fissure, receives Ven. 

 basilica and Nn. ulnaris and cutaneus intern., and connects the 

 uniting tissue of the axilla with that at the bend of the elbow. 

 4. Sheath for caput long. m. tricipitis at the superior half. It 

 is stretched by m. pectoral, maj. and latissim. dorsi. 



B. Muscles of the Fore-arm. 



a. On the anterior or flexor surface. 



a. First layer. 



300. 1. Pronator radii teres. 



Pos.: oblique from above to below, from within to without; 

 external to M. palmar, long, and flex. carp, radialis ; covered 

 by N. median, and Art. ulnaris. Or. : Condylus internus hu- 

 meri [_ and ulnar border of coronoid process] ; externally M. bra- 

 chialis intern, and biceps. Ins. : Centre of the radius (in front 

 and on outside) covered by M. supinator longus. Use : rotates 

 the radius inwards. [Nerv. median, perforates the muscle.] 



Nerves : medianus. 



301. 2. Flexor carpi radialis (s. radialis internus). 



Pos. : next to the last described muscle, internally ; with a 

 strong tendon projecting out beneath the skin, on its external bor- 

 der the Art. radialis (Pulse). Or.: Condyl. intern, humeri ; 

 internal to M. pronat. teres. Ins. : Basis of os. metacarp. II. 

 Use: to flex the hand towards the radial side. 



Nerves: medianus. 



302. 3. Palmaris longus (sometimes wanting). 



Pos. : the spindle-shaped belly in a groove upon flex, digitor. 

 sublim., and close to the last muscle, internally, with a long su- 

 perficial tendon in a strong sheath. Or. : Condyl. intern, humeri. 

 Ins. : Jlponeurosis palmaris. Use : stretches the aponeurosis 

 palmaris and flexes the hand. 



Nerves : medianus. 



303. 4. Flexor carpi ulnaris (s. ulnaris internus). 



Pos. : on the inner border of the Ulna. Art. ulnaris at first 

 beneath it, then along the outer border of its tendon. Or. : Condyl. 

 intern, humeri, and Olecranon (internal border ; beneath it nerv. 

 ulnaris). Ins.: Os pisiforme. Use: to flex the hand towards 

 the ulnar side. 



Nerves: ulnaris. 



