The economy of the animal kingdom, considered anatomically, physically, and philosophically

391쪽

ns many anomalieS Oecur in the auricles, and in tho right auricle particularly, So, in Order that the auricular blood may sud an ovilet in ali caSes and under eVery circumStanee, nnumber of orifices are provided, through Whicli this biood canbo thrown oui, sui tably to ali diversities of statu. Is We compare the Origins Of the coronary vesseis With theouileis of the fame, it Will be evident that tho blood os tho right fido of the heari is transferrest immediately into the norta, and tho blood of tho test fido of the licari into the right auricio; much as Was the case in foetes life by means of the foramenovale and ductus arteriosus; sheWing that the coronary Ve8Selsand their mouilis, relatively to the determinations of the quantityos blood running through them, aro substituted in place of the foramen Ovale and ductus arteriosus; the channei and modo oscirculation only being changed. Aud this, in ordor that tho Superfluous quantity os arteriat, or the superfluous quantity os venous blood, tu this place of concourse, may Πot injure Ordestroy the natural state of the Lingdom, subjeci as it is tofuch frequent mutations.

Henco it is olear, that Deillior the motion Os the heari, uor the circulation os the blood, cari subsist sor any longili Os time, unie88 the peculiar vesseis of tho heari that dis hargo the blood into the aorta, and those that discli argo it into the right auriclo,

392쪽

expanded und the aorta compressed, because at that time thetorrent is dri ven OnWards throuo the arteries, so that noue butthe superfluous Or refluent portion can regurgitate into the ori

pletely bellind the valves, can scarcoly admit the blood exceptduring the heari's diastole, it is certain that nature, in Order to

393쪽

bo consistent With herseis, must be presumed to have proscribe the samo conditions in ali instances; and this the rather, beeauso although these arteries operi above the Valves, yet not only arethey, as Fantoni intimates, most conveniently silualed for tho

hestri's contraction, it seems that they can admit litile or none Os it, On account of the Strong constriction Os the fibres of thelieari itself Lut those sagacious authors, the Surmise of One ofWhom, and the Opinion of the other, have draWn me into this

spicuousty above their borderS. . . . ThiS I State the more readily, hecause I am sure it is Weli linoWn . . . that the fame thing hasbeen observed by those experienced an atomisis, Bartholomaeus Eustachius, Richard LOWer, and Raymund Vieussons. For in their Ρlates . . . they, in common With Andreas Vesalius undother learned professors, . . . have depicted both orifices of these

Whether any, and What, varioty, in the motion and flow of the

394쪽

blood through the coronary arterius, is produced by the Vari etyos siluation in tho orifices, is a question Os no Very eaSy Solution n. 387). But granting that both, or either, of the Orifices, may be parily, or, as rarely happens, Wholly above themargins of the Valves, as they appear in the flaccid heari asterdeath, still We must remember, that the valvular tunic, thoughnOW dead and contractest, is so capable of elongation, that theslightest forco is sufficiunt to extend it Over the orifice; as Wemay See by Sostly passing the finger over the tunic, Whicli Willthen not Only close tho soramen, but rench boyond it to the distance of Some lines, ns I myself have found upon experiment in the hearis of more than thirty animal s. Τhis Will appear to bethe more certainly the case, Wheri We consideri that at the time Whon the systole of the heari presses the bl OOd thither, the ventricle comes nenrer to iis artery, and thus enabies the valve tomove higher up : and at the fame time the living volume os blood in the artery inys the valve flat, and extends the Wali towhicli it is affixed, Whilo the orifices remuin in their place. The

Cular, mOVe te, and in great part Dee, but nevertheless attachedio, and continuous With, the base of the hestri, and in three places continuous With the parietes of the great arteryV n. 387).He has also caresully observed the manner in Whicli these valvesare attached to the walis of the aorta. In the post mortem examination os children,' ' says he, We found ench connexionos two of the valves together, With the norta, exhibiting a Verynnalogous appearance to the clitoris in semale abortions, forrai sed aud crested oblong sutures adhered to the arteries, With Whicli they were united by firm and strong bands Os carneO- tendinous fibres, conveniently placed in eaol, of the curvilinearangles of the valves; the loose borders of the valves being there- by attached to the more solid Walis of the arteries. But thesesibro uS bands are produced further, and j inest With the fascicles of fibres that . . . constitute the circular tendons.' De Molu rilis, &c., lib. i., prop. 33.) From this description it is very evident, that When the artery sWolis and is pushed forWards, the ValVeS are extended over the orifices, and that at the fame time

' Lancisi is here speuking of his observations in the bodies of children Who died

396쪽

propelled by the systole of the heari, is not in the fame line

With the direction os the coronary arteries, but On the contrary rmS SO acute an angle With them,-that only a very smaliquantity of the stream cati flow ut that time, and in that direction, into the coronary arteries. But On the contrary, kc. kc.' n. 387.ὶ A similar law oblatus With regarn to the duci belWeen the baseos the heari and the large coronary orifice of the right auricle; for the systole of the right ventricle is performed in the fame manner as the systole of the lest ventricle; so that it Would appear that One foramen is Opened by a force and according to alaW similar to that by Whicli the Other is opened : honce thenotion of Ono being given, that of the other is given. And on both sides the foramina are placed as it u ere beside the centres of the

side, and of the vorta On the Other; so that the foramina onboth sides are ut onee compressed and closed, and at Once dr unpari and Opened. 6. Since, theres ore, during the systole ostho hoari and the diastole of the great artery, the blood cannot be forced into the coronary Vesseis, there may perhapS be Someroom for doubting, Whether it does nos return as AOon as thelieari returus to iis diastole, and the norta to iis systole, accord- ing to the second clause of this article; for the valves being thenthrown back, and the base of the heart also receding, the Orifices aro laid bare and open. But stili this Would not fuit thoartery When it has sustained a loss os ali iis sorces. It Would boto cluim for it a DeW action altogether different Dom What it exercises On the ramifications of the system; nay, it Would be toclaim for it, after the discli arge of nil iis functions, a Stronge inVerted, and retrograde action, iapon a b Ody the most muscular

397쪽

so-callud vetus With the arteries; as We usualty sind in tho bodyin generat. A tincture injected into the arteries novor colors the voltis, and that injected into the veins nevor colors the nrtorius ; but is the vetus Were empsy, they Would continue emptyastor the arteries Were injected. In this respect the former have not the condition Or character Os arteries, nor the lalter of veitis; a circumstance Whicli indicates rather that both classes of vosselsare similar in Liud, and arise Dom the beari and Dot hom the

tricte, it Would Do longer have tho poWer of erecting or arOHSingilself; sor it could no longor demand of the noria What the norinhad not to give; iis motion there re WOuid be SOOn postponed indefinitely, and itself consignen to certain death. ΜOreoVer, ali that portion und nil those motive fibres Where We find no arteries, but only Veius, sor instance, Dearly throughout the right ventricte,) When destituto os arterial blood, Would never be exciten to action. It malles litile or nothing for the argument toSay, that one vesset is an artery, because iis orifices Open into the aorta, Or Origin os nil the arteries, and that another is a Vein, because it Opens in the right auriete, Or place of termination os ali tho vultis; sinco the right ventricle as Weli as thelest, and primarily also the foramen ovale, a re siluated at thebeginning of the artorius aud termination of the vetus. But sortite salie os distinctutiss. I Will stili cali tho coronaru ve8Seis that

communiente With the aorta, arteries, and those that communicate With the auricles, vetus; according to the Common HSago.

398쪽

403. For there are lillle columns and lacunoe in the ventricles unit auricies. This is pluin Dom tho baro inspection Of the in-8ide of the heari, in Which Wo ut Once sue eminenceS, littio CaVerns, inequalities, as it Wore largisti and tesser plicatures, especialty in the right ventricto; in Whicli indoed, in the heartof the sheep, I have rectioned more than fifteen, bosides theneshy eminenco or column Whicli Lancisi calis the transverse column or flesby beam' n. 388). In the lost ventricle, hoWDVer, these columns, and the lacunae undor them, aro seW in number. In the auricles they are numerous, Since that partWhicli is properly the aurictu, and projecis beyond the border Os

lacerti. They are moreover guarded by tricuspid valves of their OWn, as those occupying the highest place in the right ventricle; and is carofulty inspected, they are found to be receptaeles and diverticula of the blood, and so many ventricles and chambersinto Whicli the heari is subdividest. 404. There are seshy ducis, or blood-conditiis. In these lacunae nud solds, We may everyWhere See orifices that penetrate into tho substance of the beari. There are some that have leaning rOOR Or Walis. In Some places there ure more, in Othersse ver. There ure somo that aro hidden, because in the sinooth paris of the heari they are overinid With iis innermost membrano. These ducis are dividen, at no great distance Dom thei rorifices, into severat Othors, and these again into stili more, and

thus they ramisy through the fleshy substance of the heart.

According to Verheyen, Vieussens relates, that he . . . Dundin the cavities of the heart udien macerated in Mater, a great

number of particular passages terminating on the inside of the Same cavities, Whicli passages he calis fleshy ducis, and says thatthey are continuous With the arteries' n. 396 . Aud Verheyen himself says, speaking of his inflation of Oue Of the coronary

399쪽

mon lacunar Or Valve, and under it a number of oscula. Thisvalvo is figured by Lancisi, De Motu Cordis, &e., inb. V., and tho soll0Wing is his description os it: There are certain sine

and minuto orifices of the coronary Vei I S, many in number, . . .

Whicli is lilio an oblong valve placed iapon many together of thelitile mouilis of the vulns V n. 388). Severat os them have been noticed by Our authors, for Whicli See especialty their plates. And there are motive Fbres; sor the heari in iis Whole compassis muscular and seshy.

under the columns. For these lacunae are SO placed as to receive

400쪽

nished Mith a common valve, or instead os it, the ducis receive an oblique insertion, and immediatoly divide into Amalter ramiscations. The blood is consequently expressed from the sesbyducis into the sbres; for When the ducis or branches pass intotheir Ieast divisions, they then become those that actualty compose the motivo fibres. 407. From the Fbres into the coronary vesseis, both arteries and Deiris. It is Woli linown that ali muscies bocomo indurated nud pale during their constriction, or doci the blood Dom their motive fibros. The constriction Of the henrt is iis systole, and during this, tho blood cannot be expressed into the lacunae, sortho blood enclosed and highly compressed, prevenis it. Theblood cannot be driven in opposition to the resistance it meeis, and to the sanguineous Stream. Hence the whole of it presses into the superficiat vesseis, in Whicli direction it finus an exit. 408. The facts ascertainen upon experiment are alone Sum cient to AheW, that there is a communication of the seshy ducis and lacunae os the heari With the coronary vesseis, both fromthe sursace toWard the interiors, and Dom the interiors toWard the surtace. There is a communication Dom the furface towarrithe interiors. The open diverticula of the vel n8,V says Lancisi, are conspicuous Within the cavities of the licari, und the nitentive anatomist Will ensily deieci them, is, through the disserent

l est ventricle tremulous and vibrating, and bubbles rising in disserent paris . . .. We threW in liquids through the anterior