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Show io76 OfflacMedulla Spinalis, or Tit/J oft/aegtzck. Book iii, mi; 0ft/9e Medulla Spinalis, or rim/9 oft/903464., 1077‘ WI reply, humbly conceiving, that many inolculations are made in the furface of the Spine; the greatei't and moll: numerous arterial The ufcofthc luOrUilleionS happenetli fomctimes above the Medufla oblongata, and often in the Neck u on the Medal/a Spinalir) an Arterial branch fomewhat greater then the ref} ta- Branches, are dilleminated through the coats of the Medul/a .sz'nalir, to give Arteries. in Beaks unite keth its courfe downward. And it is worthy ofour reinark,that in Bealls the vertebral Arteries unitethemfelves upon the Medullzz Spinalirjn an acute angle, ;[ a vital ambient heat, which is rendred‘more foft, as the over-halty courfe of in the Med!"n Ipi'mrlw. and then parting with each other for a little fpace, approach the confines Medulla, f0 that where the Trunks of the vertebral Arteries are united (that The rent. bral Artci its on each lick: of the Medulla, and thence l'peak their returns and meet each other as they began in an acute Angle, making a Figure not much unlike a rRamboialer. And the reafon, as I humbly conceive, may be probably this, Why the vertebral Arteries in their intermedial {ieps down the Neck, The Arteries of the Spine do ui‘tcn inofculare and reRmhlc a Chain of Rings. rendred more gentle, as {'omewhat intercepted in the diverfe windings and many interceflions palling between the Arteries and Veins, as fuppletories to turnings of the vertebral Arteries. thelall, to propagate the continued motion of the Blood, lell: too exube- The Third branch belonging to every vertebral Artery, as foon as it hath made its entrance through the feverallnternodes into the Spine, is difpenfed into the fore part of it, where it hath a double proceflion toward the Left mCflL Arteries of the Spine item to he wrought after the manner of Network. the lmaller Channels of the ferous Liquor, and intercept its intercourfe with of this vertebral Artery palling tranfverlly from either fide, are united by an Analiomolis, in which both Branches have a correfpondence one with another, fo that all the Arteries conveyed down the whole length of the Spine, mutually affociating in divers inofculations, do imbrace and receive each other, fomewhatrefembling a chain of many Rings, mutually linked toge~ the Nerves, impairing the Senfe and Motion of the dependant mufcular parts. The medullary Sinm defcending on both fides of the Spine, from the up. pcherteber of the Neck, to the lowelt of the Loins, ldoth much refemble in Figure that of the arterial Plex, only I conceive, this confil'teth of many unequal [ides , and that of more various concatenated Orbs; formed, as Iconceivc, after this manner, every Sin»: wheeling round, till is it conioyncilliyacommifi'hre of the vertebral Vein, perforated into the 8mm, from thence receiving fireams of Purple Liquor. . ther, as Dr. Willi: fancieth it. Thefe numerous Arteries branching themfclves overthwart from every invarious continued Marauders towards the 0: flzcrnm; and if an injection be cc- lebrated into the Aorta, and from thence into the vertebral Branches of the ' Spine, receiving the tincture, it will give a pleafant profpeét to behold the many exedrical Figures of the Arteries, feared immediately one below another, after the manner of Network,rarely wrought by diverfe Branches, which often meeting with each other, and then parting again, make various flexures, and yet ever oblErve an order of fix unequal fides, which is confpicuous in every Figure, which holdeth a kind of uniformity one with another. And this admirable Plex of Arteries climbing up to the rep of the Spine, containeth Two Branches, [booting themfelves firaight upward into the Arteries of the Spine are implanted in- totht IL": Nubile. The Arteries meet and make numerous Amrflomfir all along thc Spine. rant a fource fhould be fetled in the fubliance of the Medu/la Spmaln,the molt wife Architeét hath confiituted diverfe Sinm,as f0 many drains, to receive and carry ofl'the overflowings of the Blood, which elfe would comprefs and flop and Right Region of the Spine, and in the middle of it the Two branches ternode of the Spine, are propagated in great length, running downward in An Experi- many different Macandcrs, giving the Blood 3. curled motion,and kindly heat, Proper for the delicate frame of the Medal/a Spiimlzér, fraught with nervous Liquor, whofe temper and courfe would foon be difordered, either by the violent motion, or extravagant heat of the Blood. . _ . . making a circumference up the Neck again in a narrow paint, that the nimbler motion of a large mafs of Blood in Brutes, may be retarded, and their rapid torrent being carried with greater force in a right current, might be ciation with each other , more and more enlarge their intermedial fpacc, The Third Branch of the vertebral Artery is difpeni'ed into the Chine. the Blood is checked by frequent inolculations of different arterial Bran: ch65, now and then allociating, and afterward partingagain, which make Having difcourfed the firlt rank of Veffels appertaining to the Spmalu Medullr,and of the various divarications, Figures,and Amflamofer of their BranchesgNow the Second and larger kind prefent themfelves, the diverfeSimi/r, belongina as well to this of the Medulla Siziualir, as to that of the Brain, which being fanked in the Spine, in a more elegant order then in the other, are [0 have acoadunation ; Firfi, as it were in a point, and then quitting their alTo. Km mirabile, and Two others tending with flexures laterally to the DH" water; but the other extremity of this Arterial plex, [hooteth along the Spine downward to the 0: facrum, and is at lafi inferred with many Capillaries into the Membranes, invefling the bones of the Spine. But fome may be fo curious as to demand a reafon, why both the arterial Branches pafling through many internodes, in both fides of the Vertebers, with oblique afcents, meet in a common Trunk, making numerous Amfiomojiar all along the Spine; and alfo why another confiderable Artery creeping through the Vertebersjs tranfmitted tranl'verlly in divers branches, which make many inofculations, both above and below, in various exedrical concatenated Figures, which are framed by the different turnings and windings of the Two tranfverfe arterial Branches. The vertebral Simu are accommodated with Two different venous Channels, the One is an in-let to import Blood from the fore and hinder furfaces of tthdullaSPinalk,into the Sinus: And the other Channel an out-let to export itoutof the Siam into the Veins; and in many Animals they converfe one with another,by tranfverfe Branches,mutually interceding the Two lateral ISI- W palling down the Spine,whofe highelt part is continued to the lateral Sm»: ofthc Brain,which is furniihed with a double Du&,the one leading into the lugular and the other into vertebral Veins. The rim of the Medulld .i‘pinrlir. The ul‘: of rho Jinur. The Firll Venous Channel belonging to the .S‘r'wur. The other v:nous Chanml, The entercourfc of [he Mimi. Bl" :3 what good are thefe Sinw: defigned P To which I take the boldnefs to 8ch this reply, That the Blood carried by the impulfe of the vertebral Ar- mics into the fubfiance of the Medulla Spinalis, is thence conveyed by venous "PCS," f0 many Sanguiduéis into diverfe Sinm,the larger Cifierns containing great referves of Blood, till a depletion be made ofthe vertebral Veins; otherwife an inundation of extravafated Blood being made in the fubl'rancc of the Medulla Spinali'r, would give a check to the motion of the Animal Liquor, iii"ling into the infiruments of ‘Senfe and Motion. _ . And thefe Sin»: being already treated of,do molt properly uiliet in the Third rank of Veffels the Veins, becaufe both the venous Duets recervrng the Blood ("anfmitted ffom the vertebral Arteries into the fubllance ofthe Mdulla Spr"" l‘ convey it into the Sinur, and from thence re-convey it, as from a larger in"fishy the more minute Channels of the venous Ducts, into the vertebral Bins, to which the venous pallages and Shaw, are not only akin in holding anintcrcourfe, as receptive of vital Liquor, fubalternately communicagflr: To cf the Spinal The Vcirl of the Medal/a .i‘piulw |