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 250 ANA T O M y. Part m The bronchialis gives a fmall branch to the neighbour- The humeral artery arifes from the lower and fore-fid.e ing auricle of the heart, which communioates with the of the axillaris, and runs backward between the head of the os humeri and teres major, furrounding the articulaarteria coronaria. The oefophagasse a^e generally two or three in number, tion, till it reaches the pofterior part of the deltoides, fometimes but one. They arife anteriorly from the aorta to which it is diftributed. During this courfe, it gives feveral branches to thefur defcendens, and are dillributed to the oefophagus, <bc. The inferior intercollals are commonly feven or eight perior portions of the anconaei, to the capful ar ligament on each fide, and fometimes ten, when the fuperior in- of the joint of the Ihoulder;, and to the os humeri itfelf, tercoftals arife like wife from the. aorta defcendens; in through feveral holes immediately below the great tuber rofity of the head of that bone. which cafe thefe run obliquely upward. They arife along the back-iide of the defcending aorta Oppofite to the origin of this humeral artery, the ax.in pairs, all the way to the diaphragm, and run tranf- illaris fends off another fmall branch, which runs in a verfely towards each fide, on the bodies of the vertebrae. contrary direftion, between the head of the os humeri, Thofe on the right fide pafs behind the vena azygos ; and and the common upper part of the biceps and coraco.afterwards they all run to the intercoftal mufcles, along brachialis; and having given branches to the vagina and the lower edge of the ribs, all the way to the fternum, channel of the biceps, and to the periofteum, afterwards joins the principal humeralis. or near it. They fend branches to the pleura,^ to the vertebral The axillary artery'having given off thefe branches, mufcles, to thofe mufcles which He on the outfides of the paffes immediately behind the tendon of the pedtoralis ribs, and to the upper portions of the mufcles- of the ab- major, where it changes its former name for that of ardomen ; and they communicate with the arteriae epiga- teria brachialU. It runs down on the infide of the arm, over the mufculus coraco-brachialis and anconaeus interftricse and lumbares. Before they take their courfe along the ribs, each of nus, and along the inner edge of the biceps, behind the them detaches one branch between the tranfverfe apo- vena bafilica, giving fmall branches on both fides to the phyfes on both fides, to the vertebral mufcles, and ano- neighbouring mufcles, to the periofteum, and to the bone. Between the axilla and middle of the arm, it is cother which enters the great canal of the fpina dorfi. Afterwards each intercoftal artery having reached the vered only by the fkin and fat; but afterwards it is hid middle of the rib, or a little more, divides into two prim under the biceps, and runs obliquely .forward as it decipal branches, one internal, the other external. Soon feends; being at fome diftance from the internal conafter this divifion, the arteries that run upon the falfe dyle, but it does not reach the middle of the fold of the ribs, feparate a little from them, being gradually bent arm. downward one after another, and are fpread upon the Between the axilla and this place, it fends off many branches to the infra-fpinatus, teres major and minor, abdominal mufcles. The fubclavian artery having left the thorax imme- fubfcapularis, fatiilimus dorfi, ferratus major, and other diately above the firlt rib, in the interftice left between neighbouring mufcles, to- the common integuments, and the portions of the fealenus, there receives the name of even to the nerves. Below the fold of the arm, it divides into two principal branches, one called arteria cuaxillaris, becaufe it palfes under the axilla. In this courfe it gives off, from its infide, a fmall bitalis, the other radialis. its upper and inner part, it fends off a particubranch to the infide of the firft rib; and afterwards four larFrom or five principal branches, viz. the thqracica fuperior, branch, which runs obliquely downward and backor mammaria externa, thoracica inferior, mufcularis, or ward over the anconsei, and then turns forward agaio, fcapularis externa, fcapularis interna, and humeralis. near the external condyle, where it communicates with a The fuperior thoracica, or external mammary artery, branch of the arteria radialis. runs down, in a winding courfe, on the lateral parts of Immediately below the infertion of the teres major, it the thorax, and erodes the ribs. It gives branches to gives off another branch, which runs from within outthe two peftoral mufcles, to the mamma, mufculus fub- wards, and from behind forward, round the os humeri; clavius, ferratus major, latidimus dorfi, and.to the upper and defeends obliquely forward, between the mufculus brachiseus, and anconasus externus, to both which it js portions of the coraco-brachialis and biceps. The inferior thoracic .artery runs along the inferior diftributed in its paffage. Having afterwards reached. eofla of the fcapula, to the mufculus fubfcapularis, teres the external condyle, it unites with the branch laft menmajor and minor, infra-fpinatus, latilTimus dorfi, ferratus tioned, and likewife communicates with a branch of the major, and the neighbouring intercoftal mufcles, commu- arteries of the fore-arm, fo that there is here a triple anaftomofis. nicating with the arterin fcapulares. The external fcapulary artery palfes through the notch About the breadth of a finger below this fecond in the fupefior cofta of the fcapula, to the mufculus fu- branch, the brachial artery fends off a third, which runs pra-fpinatus and infra-fpinatus, teres major and minor, down towards the internal condyle, and communicates and to the articulation of the fcapula with the os humeri. with other branches of the arteries of the fore-arm, as The internal fcapularis arifes from the axillary artery we lhall fee hereafter. near the axilla, and runs backward, to be diftributed to About the middle of the arm, or a little lower, much the fubfcapularis, giving branches to the ferratus major, about the place where the brachial artery begins to be covered by the bic:ps, it fends off a branch,diftributed which is to the axillary glands, and to the teres major..