| XXX | (240) | XXX |
ANATOMY. Part IV. 240 the thyroid glands. About two fingers breadth highto the root of the nofe, and communicating with its fel- erto up, it detaches a middle-fized branch, which low from the other fide* gives feveral fmail Veins to the terally towards the larynx, and may be named runs laholes of the olfa nafi. The fecond branch runs up on the fore-head, by the turalis. guttural vein divides chiefly into three branches; name of vena frontalis, and is diftributed to each fide. theThis lowelt of which goes to the thyroid gland and neighThe third branch ente'fs the orbit in a winding courfe, bouring mufcles ; the middle branch to the larynx, mu{on one fide of the cartilaginous pulley, and communi- culi thyroidsei, <&c. and the third runs upward to the cates with the finufes of the dura mater, by the orbitary great communication between the two jugulates. finus of the eye. the fame diltance upward, almolt oppofite to The fourth branch goes along the mufculus fuperci- theAbout hyoides, the internal jugular gives another branch, liaris and the upper part of the orbicularis, to the fmail whichos fends rami to the muicles belonging to that bone, 6r external angle of the eye, to communicate with the and others which communicate with the foregoing branch. vena temporalis, and with that vein which runs along the This other branch runs upward toward the parotid gland tower part of the orbicular mufcle. and angle of the lower jaw, where it fends communicaThe pofterior or fuperior external jugular vein runs up ting branches forward and backward to the two external toward the parotid gland, and lower anterior part of the jugulares. eye, giving out feveral branches towanf each fide. The internal jugular fends another branch backward^ At its origin it fends out pofterioriy, a principal which is diftributed to the occiput, where it communibranch, with its ramifications, to the mufcles which co- cates with a branch of the vertebralis, and, through the ver the fcapula and joint of the humerus, commonly pofterior maftoid hole, with the lateral finus of the ducalled vena mufcularis, mater. A little higher, it gives off the vena cervicalis, which ra Afterwards it reaches the foramen lacerum of the bagoes to the vertebral mufcles of the neck. bending a little, and fending off fmall twigs to Near the cervical vein, but a little more outward, it fis cranii, pharynx and neighbouring mufcles. gives off fometimes the fmall vena cephalica, which runs theThe vertebral rein anfes pofterioriy from the fubcladown between the pe&oralis major and deltoides, and u- via or axillaris, fometimes by two Items. nites with the vena cephalica of the, arm. firll and principal Item gives out a branch, called Backward it detaches the vena occipitalis, which is di- venaThecervicalis, which is diftributed to the neighbouring flributed on the occiput ; it likewife fends out a final! mufcles, and afterwards runs up through the holes of the vein, which enters the cranium by the poftefior maftoid apopbyles of the vertebrx colli. hole, and terminates in one of the lateral finufes of the tranfverle 1 he other item of the vertebral vein runs up on the dura mater. of the vertebras; and having reached the fourth, or Having reached as far as the parotid gland, it forms fide fometimes higher, it runs in between the tranlverfe apocommunications with the anterior external jugular, under phyles that vertebra and the fifth, to join the firft or the angle of the lower jaw; and then palfes through the principalofItem. parotid gland, between that angle and the condyle, gi- Thus the vertebral vein accompanies the artery of the ving off a large branch which communicates with ano- fame name, fometimes in one trunk, fometimes in feveral ther branch common to the internal and anterior external Items, through all the holes of the tranfverle apophyies of jugulars. vertebras colli, all the way to the great foramen ocAfterwards it pafies before the ear, taking the name of the cipitale, communicating with the occipital veins and fmall vena temporalis, which is diftributed to the temples and occipital finufes of the dura mater. lateral parts of the head, towards the occiput and fore- In its palfage it gives off one branch, which enters by head. polterior^ondyloid hole of the os occipitis, and comThe temporal vein of one fide communicates, above, the with the lateral finus of the dura mater. with its fellow on the other fide; before, with the vena municates As thefe veins run through the hoks in the tranfverfe frontalis ; and behind, with the vena occipitalis. Oppo- apophyfes, they lend branches forward to the anterior fite to the ear, it gives out a large branch, one ramus of muicles of the neck, and to the fmall anterior mufcles of which runs under the lower edge of the zygoma, and the head. then returning, communicates with another ramus fro.m Other branches go likewife outward and backward to the fame jugularis, a little below the condyle of the lowthe mufculi tranfverfales and vertebrales colli; and iner jaw. Behind this condyle, it gives branches to the temporal ward to the great canal of the fpinal marrow, where they mufcle, to the neighbouring parts of the upper jaw, and form finufes, which communicate with thofe on the other lide. to the infide of the lower jaw. The internal jugular vein is the largcft of thofe that Thefe vertebral finufes are pretty numerous, and placed one above another all the way to the occiput; the go to the head. It runs up behind the fierno-maftoidaeus and omo-hy- lower communicate v/ith the upper; and at the great otdscus, w hich it croffes, along the fides of the vertebnfc foramen of the os occipitis there is a communication beof the neck, by the edge of the longus colli, to the fof- tween them and the occipital finufes of the dura mater. fula of the foramen lacerum of the bafis cranii. The fubclavian vein having fent off the branches albeThe fiift branches which it fends off are fmall, and go ready defcribed, goes out ox the thcrax, and palfesfore
