MUSCULAR SYSTEM. 143 



EPicoNDYLO-METACARPEu s. — Fleiof meldcarpi interims. 



Situation. — Postero-internal side of the arm. 



Form. — Loiioer, but not so broad as the preceding muscle. 



Attachment. — Superiorly, to the internal condyle of the hu- 

 merus ; adherino- to the capsular ligament of the elbow joint. 

 Inferiorly, to the head of the internal metacarpal bone. 



Relations. — Posteriorly and internally, with the faschia and 

 skin ; internally, with the last muscle ; anteriorly, with the radius, 

 and humeral blood-vessels and nerves. 



Structure. — Superior attachment, tendinous ; in part, fleshy. 

 Surfaces aponeurotic. Just above the knee it sends off a narrow 

 flattened tendon, which passes through a tendinous theca. 



Action. — To bend the leg. 



ULNARis AccEssoiMus. — Flcxor Qccessorius subliniis. 



Situation. — Posterior part of the arm. 



Form. — Elongated ; thick ; fusiform. 



Attachment. — Superiorly, to the postero-internal part of the 

 ulna, below the olecranon: inferiorly, to the tendon of the flexor 

 perforans. 



Direction. — Oblique: from above downwards; and from 

 without inwards. 



Structure.— '&uY>Qnov attachment tendinous in part, but mostly 

 fleshy. Inferior surface, aponeurotic. A little above the middle 

 of the arm it sends off a tendon which passes under the posterior 

 annular ligament of the knee, and there unites itself to the 

 tendon of the perforans. 



DEEP POSTERIOR BRACHIO-CRURAL REGION. 



The following muscles constitute the deep-seated flexors : 

 they lie anteriorly to and are concealed by the superficial. 



FLEXOR PEDIS PERFORATUs. — Epicoudj/lo-phalaiigeus. 



Situation. — Deep-seated in the posterior part of the arm. 



Form. — This and the flexor perforans form one thick, com- 

 pact, cylindroid fleshy mass ; the tendons issuing from which are 

 long and flattened, and adapted by convexity and concavity of 

 surface to each other. 



Attuckmoit. — Superiorly, (and in common union with the fol- 

 lowing muscle) to the lower side of the internal condyle : infe- 

 riorly, to the upper and back part of the os coronse. 



Relations. — Posteriorly, to the three flexores raetacarpi and 

 flexor sublimis ; anteriorly, to the radius and flexor profundus. 

 Along the antero-internal border run the radial blood-vessels 

 and nerves. 



