////: .\\TEiiion rr.v.i r.ir.i. en 



metacarpus. A number of muscular and subcutaneous branches enter this 

 vein. 



It has the same origin as the posterior radial veins. Its superior or 

 terminal extremity bends forward, close to the trunk of tho epicondyloid 

 artery, and goes to tho inferior extremity of tho humeral vein. Frequently 

 the ulnar vein is double in the latter portion of its track, and between the 

 two branches lies the artery. It always communicates at this point, by 

 one or more branches, with the deep muscular vein. 



5. Superficial Veins of the Fore-arm. 



Placed outside the fibrous sheath formed by the antibrachial aponeurosis, 

 hich are principally two in number, are maintained against 

 the external face of that membrane by a thin fascia which separates them 

 from the skin. 



A. MEDIAN, OB INTERNAL SUBCUTANEOUS VEIN (Fig. 293, 31). This is 

 also one of the vessels selected for the operation of phlebotomy. It is tho 

 continuation of the internal metacarpal vein, ascends from the inner face 

 of tho carpus to the superior extremity of the fore-arm, by crossing the 

 radius in a very oblique manner, and terminates in two very large 

 branches, the posterior of which is the basilic vein, and the anterior the 



i; jJmli,- f in. 



The basilic vein traverses the sterno-aponeurotic (transverse pectoral) 

 muscle, to aid in forming the humeral trunk (Fig. 293, 34). 



The cephalic, or plat vein, crosses the superficial band of the biceps or 

 coraco-radial muscle, is lodged in the space comprised between the levator- 

 lunneri and small pectoral muscles, and afterwards opens into the jugular 

 vein (Fig. 293, 35). 



B. SUBCUTANEOUS, OB ANTEBIOB RADIAL VEIN (Fig. 293, 32). Less 

 considerable than the preceding, this vein arises at the carpal region, in its 

 course occupies the anterior face of the fore-arm, and terminates in uniting 

 its superior extremity either to the subcutaneous median or the cephalic 

 vein ; the last is most frequently the case. 



6. Metacarpal Veins. 



Throe in number, as we know, these veins are distinguished into in- 

 ternal and external collateral of the cannon, and deep or interosseous c Jldttral. 



A. INTERNAL COLLATERAL OF THE CANNON. More voluminous than tie 

 .th.-rs, this vein passes from tho vicinity of the fetlock along the flexor 

 tendons, accompanied by tho principal artery of tho cannon and the 

 external plantar nerve, places itself in tho special sheath which envelops 

 the common trunk of tho interossoous arteries to tho inside of, and In-hind 

 tho carpus, to be continued in tho antibrachial region by tho met linn 

 subcutaneous vein, after communicating with the other mctarcarpal veins 



293, 30). 



B. EXTERNAL COLLATERAL OF THE CANNON. Si tuatcd opposite the 

 preceding to tho external side of the flexor tendons, in company with the 

 corresponding plantar nerve tho external collateral of the cannni follows 

 th:it nerve to near tho trapezium, and then separates into several n ticuhitt <1 

 branches which anastomose with the internal collateral, from which proceed 

 tlif n 1 nar nn-1 iutcnu I or posterior radial v 



2 a 2 



