Page:Encyclopædia Britannica, first edition - Volume I, A-B.pdf/287

 Part IV. ANA T O M Y. 241 fore the anterior portion of the mofculus fcalenus, and fore-arm, oppofite to the intcrrofTeous ligament, and is between the firft lib and the clavicle, to the axilla. called vena cubiti profunda. It goes to the neighbourThrough this courfe it takes the name of vz/ia axillaris, ing mufcles, and communicates^ with the other veins of and gives off feveral branches, the chief of which are the fore-arm. The-mediana cephalica fometimes fends a long branch, called radialis interna, which lies the vente nwafculares, tboracicae, and vena cephalica. down The rnufculares, are dihributed to the middle portion almofi: parallel to the radialis externa. of the mulct!ins trapezius, to the angularis, infra-fpina- Afterwards the cephalica, having reached the extretus, and fubfcapularis; and as fome of thefe branches mity of the radius, is diftributed, by numerous areolae, go to the fhoulder exteriorly, others interiorly, the ve- almoft in the fame courfe with the radial artery. nae fcapulares are diftinguilhed into external and internal. A particular branch goes out from it, which runs more A little before the axillaris reaches the axilla, it fends or lefs fuperficially between the thumb and metacarpus, out the venae thoracicas, one of which is fuperior, called by the name of cephalica pollicis. The areolae furni/h alfo mammaria externa, and the other inferior. It like- the interrofleous mufcles and integuments, and commuwife fends rami to the mufculus fubfcapularis, teres ma- nicate with a final! ramus from the bafilica, called by the jor, teres minor, fupra-fpinatus, latiffimus dorli, ferra- ancients Salvatella. tus major, pedoralis minor, pe&oralis rnajor, and to the The bafilic vein fends off firfi: of all, under the head of the os humeri, a pretty large branch, which paffes alglands of the axilla. The axillaris having reached the fide of the head of mofi tranfverfely round the neck of that bone, from the os humeri, produces a branch, mmedvena cephalica, within backward, and from behind outward, running and afterwards runs along the arm by the name of vena upon the fcapula, where it is ramified on the deltoides, and communicates with the venae fcapulares externae. baftliea. The cephalic vein, which is a branch of the axillaris, This branch may be named vena Jub-humeralis, or arat a final! diftance from its origin, joins the fimll cepha- ticularis. lica, which runs down from the fubclavia, or jugularis This articular vein fends down two principal branches, externa. one of which runs along the infide of the bone, to which, The great cephalica runs down between the tendons and to the periofteum, it gives fmall veins. The other of the laft mentioned mufcles, and along the outer edge turns forward, toward the middle of the arm between of the external portion of the biceps; communicating the bone and the biceps, and communicates with the.cefeveral times with the vena bafilica, and fending fmall phalica. rami on each fide, to the neighbouring mufcles, fat and Below the neck of the os humeri, near the hollow of fkin. the axilla, and behind the tendon of the pe&oralis maA little below the external condyle of the os humeri, jor, the bafilica fends out a confiderable branch, which it detaches a branch backward, which runs up between runs down on the fide of the brachial artery, and furthe mufculus brach'alis and the upper portion of the fu- nifhes the neighbouring mufcles on both fides. This vein pinator longus, and afterwards bends back between the iS named profunda braehit. os humeri and anconaeus externus, where it communi- Immediately afterwards, the bafilica detaches two or cates with fome branches of the bafilica. fmall veins, which run down very clofely joined to Having reached very near the fold of the arm, it is three the brachial artery, furrounding it at different diftances divided into two principal branches, one long, the other by fin all twigs which communicate with each other. ihort. The long branch is named radialis externa, and Thefe fmall veins, which often arife from the profunthe fhort one may be called mediana cepbalica, to diftin- da fuperior, communicate with the bafilica and cephalica; guifh it from another mediana, which is a ftiort branch and having reached the fold of the arm, they divide like of the bafilica. artery; and the fame divifions are continued along The external radial vein runs along the radius between the whole fore-arm. the mufcles and integuments, giving olf branches towards theAfterwards the bafilica continues its courfe alon'r the inboth fides, which communicate with othdr branches of fide of the os humeri, between the mufcles and integuments, the lame vein, and with fome from the bafilica. forming many communications with the vena profunda and The mediana cephalica runs down obliquely toward cephalica, and fupplying the mufcles integuments. the middle of the fold of the arm, under the integu- Having reached the inner condyle, and having fent off ments, and over the tendon of the biceps, where it joins obliquely, in the fold of the arm, theandmediana bafilica, a Ihort branch of the fame kind from the bafilica. it runs along the ulna, between the integuments mufFrom this anaftomofis, a confiderable branch goes out, cles, a little toward the outfide, by the name ofandcubitawhich runs down on the fore-arm, uniting on one fide lis externa. wi*h the vena cephalica, and communicating on the obafilica having at length reached the extremity of ther with the bafilica, by feveral irregular areolte. The theThe fends fevera.1 branches to the convex fide of name of mediana is given to this large branch, as well the ulna, carpus; of which, named Salvatella, goes to as to the two Ihort ones, by the union of which it is that fide of theonelittle finger next the ring finger, having formed. firfi communicated with theon cephalica, From this union of the two lateral medians, and venal areolae confpicuous the back ofbythemeans hand.of theIn fometimes from the origin .of the mediana media, a the other fingers this vein follows nearly the fame courfe branch goes out, which runs down on the infide of the with the arteries. Von. I. No. ii. 3 In 3P