A systeme of anatomy, treating of the body of man, beasts, birds, fish, insects, and plants illustrated with many schemes, consisting of variety of elegant figures, drawn from the life, and engraven in seventy four folio copper-plates. And after every part of man's body hath been anatomically described, its diseases, cases, and cures are concisely exhibited. The first volume containing the parts of the lowest apartiments of the body of man and other animals, etc. / by Samuel Collins ...

CHAP. XXXI. Of the Arteries of the Heart.

HAving spoke of the Heart and Blood, it may be now methodical to discourse the Arteries and Veins, as so many Membranous Cylin∣ders, exporting and importing Vital Liquor from and to the Heart.

The Arteries of the Heart are Trunks, attended with smaller and smaller Branches, and Ramulets, as so many fine Tubes of different sizes, transmit∣ting Blood into the Heart, Lungs, and other apartiments of the noble fabrick of Humane Body.

The Heart is furnished with three Arteries, the Pulmonary, the Aorta, * 1.1 and Coronary. The first being inserted into the upper part of the right Ven∣tricle, hath its Orifice leading into the Lungs, whose substance is adorned with numerous Divarications.

The Origen of the Pulmonary Artery is beset with Tricuspidal Valves, * 1.2 hindring the reflux of Blood out of the Lungs into the right Chamber.

The Aorta hath its Orifice placed about the left Ventricle, * 1.3 which first conveyeth Blood into a common Trunk, which hath its first entrance guard∣ed with Semilunary Valves, to give a check to the Retrograde motion of the Blood out of the Aorta into the right Ventricle.

The Orifice of the great Artery is contrived with great Artifice, lest the Blood conveyed with a brisk Impulse, should be unequally distributed into the parts of the Body; and therefore Nature hath made the Arterial Channels of Blood somewhat winding, so that it cannot be transmitted with a rapid current into the Brain, lest it should overflow it and destroy the Animal Functions, by an Apoplectick Fit. To obviate this destructive disease, the All-wife Agent hath so ordered the Trunk of the Aorta not far distant from the confines of the Heart, that the Rivulets of Blood should not be carried in a straight course, but in a kind of Meander, into the Axillary and Cervical Arte∣ries; And in the middle space between the left Ventricle and said Arterial Chan∣nels, the great Artery taketh its progress with a Circumvolution, that its crooked Angle might sustain the first brisk impulse of the Blood, and divert the greater stream (toward the descendent Trunk of the Aorta) which else would be imported with great violence through the ascendent Trunk into the Carotide Arteries, and make an inundation of the Brain.

The Coronary Artery sprouteth out of the Trunk of the Aorta, * 1.4 imme∣diately after it taketh its rise out of the left Ventricle of the Heart, before it perforates the Pericardium, and encircleth the Base of the Heart, and trans∣mitteth many branches toward the Cone, especially in the left Side.

This Artery receiveth Blood out of the Trunk of the Aorta, and trans∣mitteth it into the substance of the Heart, and chiefly toward its outward surface, which is then discharged out of the Parenchyma of the Heart into the Extremities of the Coronary Veins, and afterward into the Trunk of the Vena Cava, and right Ventricle of the Heart.

If any be so curious as to make a search into the first formation of the Ar∣teries, I humbly conceive they are produced after this manner; * 1.5 The Vi∣tal Liquor receiveth its first Rudiment in the Seminal Matter, wherein

the most select part being Colliquated by heat, doth separate from the more gross, and not move promiscuously at large, but is confined within proper Channels which first take their progress toward the rough draught of the Heart, by whose motion it is impelled through the Retrograde Tubes, which are the first origens of the Arteries, as being produced out of the more clammy Particles of the Genital Matter concreted into Concave mem∣branous Vessels, importing Vital Juice into the ambient parts of the Semi∣nal Colliquated Liquor, to give it life and heat in order to the rough draught of the parts belonging to several Animals.

Arteries, as to their Figure, are Cylinders, having oblong, round, con∣cave bodies fitted for the reception and transmission of Vital Liquor from the Center to the Circumference, from the Heart to the ambient parts of the Body.

Their substance is framed of numerous small nervous and membranous Fi∣laments (interspersed with fleshy Fibres) closely conjoyned to each other, * 1.6 produced originally out of the more tensil and clammy parts of the Se∣minal Liquor; These Fibres intersect each other in various postures, some being right, others oblique, and a third transverse. This Hypothesis of Fibres integrating this membranous Tube, may be proved, as I humbly conceive, by reason if the Vessels were made of one continued concreted substance, without the texture of various Filaments, their Coats would not be distended with a quantity of Blood, without Laceration; So that the numerous minute Filaments being tough and flexible, being of a firm pli∣able nature, can give way and grow swelled by a large proportion of Li∣quor immitted into this membranous system of Fibres, without any viola∣tion of their round minute Bodies.

The Compage of the Aorta, * 1.7 and its Branches, is composed of four Coats. The first and outward Tunicle is propagated from the Pleura, in the middle Apartiment, and from the rim of the Belly in the lowest, and is destitute of it when it enters into the Viscera; This Coat is of a Ner∣vous constitution, as integrated of many Nervous Fibres, finely spun, and curiously interwoven with each other, after the manner of Network, wrought in the inside.

The second Coat of the Arteries is affixed to this retiform Tunicle, * 1.8 and is a Membrane beset with numerous minute Glands, overspread∣ing its inward surface and is adorned in its upper side, with a retiform plex of divaricated Fibrils; this Tunicle, as I conceive, is propagated from the Coat (investing the Heart) to which it is continued.

The third Tunicle of the Arteries is more firm and thick, * 1.9 then the out∣ward, especially in the common Trunk of the Aorta, conjoyned to the left Ventricle of the Heart, that it might contain the hot spirituous thin blood im∣mediately received from the left Ventricle without the dissipation of its Vo∣latil Spirituous parts, and as the Arteries are more distant from the Center of the Body they grow more thin and soft.

This Coat is furnished with many transverse, or rather circular fleshy Fi∣bres which are very conspicuous in the common Trunk of the Aorta, re∣lating to a great Beast. Learned Rolfinchius, conceived the substance of the Arteries to be wholly Membranous, as not having any fleshy Fibres; Lib. 6. Anatomes, Cap. 4. Ait ille, nos statuimus substantiam Arteriarum esse 〈 in non-Latin alphabet 〉〈 in non-Latin alphabet 〉, Membraneam, ne{que} apte posse referri ad aliquam dictarum partium, sed esse propriam & sui generis, similitudine tamen Coloris & Crassitiei aemulari Car∣tilagines. Fibrae in hac Arteriarum substantia non dantur propriè dictae; but

with deference to this worthy Author, I humbly conceive this Conjecture opposeth Autopsie, for we may easily discern the fleshy Fibres in the com∣mon Trunk of the Aorta, when boiled. Farthermore I apprehend that the fleshy Fibres of the Arteries may be clearly evinced by Reason, because if the Arteries were not beset with Carnous Fibres, when they are dilated by a great quantity of Blood in strong Pulsations, they would remain in the same distended posture, had they not a power to restore themselves to their former tone by the power of Fibres. And I farther believe, that the cause of an Aneurism, that when the second Coat of the Arteries, and its Fibres being broken, the Blood hath a recourse to the outward Tunicle, which being soft, is easily distended, whence ariseth oftentimes a large bea∣ting tumor.

The fourth Tunicle of the Arteries, as Great Galen hath observed, * 1.10 is as it were a thin membranous Tunicle, resembling a Spiders Web, which is visible to a curious Eye making inspection into the inward recesses of the great Artery, and seemeth to be the off-spring of the inward Tunicle in∣vesting the inside of the left Ventricle, as being a continuation of that thin Coat. This Tunicle is Membranous, as composed of many Fibres of the same kind, some of which being carried in length, do intersect the annular fleshy Fibres, according to right Angles.

As to the substance of the Arteries, some hold it to be wholly Nervous, * 1.11 as being composed of many Fibres, which cannot be the sole off-spring of Nerves, by reason the Arteries are endued with little or no sense: Others conceive the Compage of the Arteries to be Cartilagineous, by reason many great Anatomists have found the Arteries near the Heart to be grisly and sometimes bony, but this is preternatural, and cannot be termed the true and proper substance of the Arteries, which is chiefly made up of many Membranous Fibres, endued with an obtuse sense, and these Fibres are pe∣culiar to the Coats of the Arteries and Veins, and to no other Membranes relating to the Body.

The Arteries seem to have a double motion, Diastole and Systole; * 1.12 The first, I humbly conceive, is produced by the systole of the Heart highly con∣tracting the Ventricles, impelling the Blood out of the right Ventricle in∣to the Pulmonary Artery, and out of the left into the common Trunk of the Aorta, and so into all Arteries; but the manner how the pulsation of the Arteries is made in all parts of the body in the same instant is hard to be understood; Learned Dr. Harvey expresseth it after this manner, That the pulsation of Arteries is performed by the impulse of the Blood, * 1.13 at the same time affecting all the Arteries, as when an immission of Breath is made into the great cavity of a Glove, at the same moment all the Fingers are distended; In Lib. de Motu Cordis, Cap. 35. Ait ille, Deni{que} Arteriarum Pulsum fieri ab impulsu sanguinis è Ventriculo sinistro, eo pacto, quo cum quis in Chirothecam inflat, omnes digitos simul videt distendi, & Pulsum aemulari: To which I make bold, with the Great Author's leave, to speak this Reply, That the Simile of immission of Breath from the Hand to the Fingers, doth not hold by reason the distance is very small between them, so that the Breath may be immediately conveyed from one part to the other, which cannot be so easily effected in the motion of the Blood from the left Chamber of the Heart into the Extremities of the Arteries, which are seated at a great distance from each other.

Learned Diemerbroeck backeth this Hypothesis by a farther argument, That the Blood being hot and thin, as it is rarefied and easily moveable, and thereupon may be impelled from the Heart into the Arteries filled with Blood. Ait ille, Anatomes Lib. 6. pag. 807, Sanguinem Arteriarum esse rare∣factum, calidum, tenuem, & hinc facile mobilem, eum{que} é Corde impelli in Arterias simili sanguine antea repletas, unde pauxillum quid è Corde in Arteriam magnam propellitur, mox ab illo pauxillo etiam necessario totum, quod omnibus Arteriis inest, simul propelli, sic{que} omnes Arterias eodem tempore simul distendi, si in Orbe stanneo, vel Scutella deponatur circulus Globulorum Contiguorum, & unus eorum manu promoveatur seu impellatur, ille proximum, alter tertium, & sic deinceps omnes eodem momento promoventur & impelluntur, ita se habet in Arteriis, in quibus una parte sanguinis mota, moventur omnes.

This famous Author Illustrates the Motion of the Blood in the pulsation of the Artery by the motion of many Bullets put into a Vessel, wherein one being moved, all do move; So that by this instance he concludeth that the Bullets move at once, which seemeth to contradict Reason and Sense, because though they be Contiguous, yet they press one another forward by a successive motion, and is done so quickly, as it seemeth to be but a mo∣ment, whereas in truth it supposeth more.

And in like manner the Blood is carried out of the left Ventricle of the Heart into the common Trunk of the Aorta, wherein it meeteth with a con∣tinued stream of Blood, which by degrees is moved by divers Channels into all parts of the Body, which cannot be effected any other way than by un∣dulating Motion, by pressing one part of the Blood forward after another from the beginning to the Terminations of the Arteries; So that these San∣guiducts being propagated in many Flexures, by reason of their numerous Divarications, must necessarily give such a check to the over-hasty current of the Blood, that it cannot be impelled from the Heart at one moment through all the Arteries, which are seated at a great distance from the Center.

Whereupon I conceive, that the motion of the Blood out of the left Chamber of the Heart, making the Diastole (vulgarly thought) first in the common Trunk, and afterward in the ascendent and descendent Trunk of the Aorta, and divers crooked branches of the lesser Arteries, is not the cause of the pulsation of the Artery, which is performed in a moment in one brisk con∣tinued motion, and not successively by way of Undulation, which suppo∣seth many Instants in which one part of the Artery is elevated after another, as it groweth distended by a great stream of Blood; * 1.14 So that I imagine the pulsation of the Arteries doth proceed from the vigorous contraction of the right and left Ventricle of the Heart, to which the Trunks of the Pulmo∣nary and great Artery are affixed; whereupon their Trunks being briskly strook by the pulsation of the Heart, their continued Coats being ever distended with Vital Liquor, have the Vibration immediately imparted to them in all parts, after the manner of an Impulse made upon one part of an extended Mu∣sical string, the same stroke is immediately transmitted to every part of it, as the whole string is made up of one continued substance of a twisted Gut.

So that, I conceive, the Diastole of the Artery, taken in a strict notion, is not made by the successive motion of the Blood (first produced in the Heart, and then carried out of it, into the common Trunk, and afterward into the Arteries, furnishing all parts of the Body) but by the Systole of the Heart, first making a Vibration in it (which I have seen in a Dog dissected alive in the Colledg Theater) imparted in the same moment to all parts of

the Arteries, which is the Pulse, commonly felt in the Wrist, and is at the same instant in all parts of the Body.

The Systole of the Arteries is their proper motion, * 1.15 as made solely in them by their peculiar power, without the assistance of the Heart, causing the Diastole, flowing from the vigorous motion, tension and contraction of the numerous strong fleshy Fibres of the Heart, but the Systole of the Arteries is a motion distinct from their Diastole, formed by the trans∣verse or rather annular fleshy Fibres of the Arteries, whereby their cavity is narrowed, and the Blood pressed through their Channels with a greater quickness.

The contraction of these circular Fibres, causing the Systole of the Ar∣teries, doth very much contribute to the motion of the Blood, flowing primarily from the Impulse, made in the Ventricles of the Heart by strong contracted fleshy Fibres lessening their Cavities; whereupon the Blood is squirted as by a Syringe out of the Right Chamber of the Heart into the Trunk of the Pulmonary Artery, and out of the Left into the Aorta, * 1.16 and then into all other parts of the Body, which is very much promoted by the motion of Carnous Fibres encircling Artery, else the Blood would have but a slow cur∣rent upward through the ascendent Trunk of the Aorta and Carotide Arteries; and especially in the small Capillary Arteries of the Brain, in which the Blood would become stagnant, if its motion were not quickned by the Systole of the Arteries, produced by the Contraction of the fleshy circular Fibres.

Notes

• * 1.1

  The Arteries of the Heart.
• * 1.2

  The Orifice of the Pulmo∣nary Arteries.
• * 1.3

  The Orifice of the Aorta.
• * 1.4

  The Corona∣ry Artery.
• * 1.5

  The first pro∣duction of the Arteries.
• * 1.6

  The substance of the Arte∣ries.
• * 1.7

  The first Coat of the Aorta.
• * 1.8

  The second Coat of the Aorta.
• * 1.9

  The third is endued with many fleshy Fibres.
• * 1.10

  The fourth Coat of the Aorta.
• * 1.11

  Some hold the substance of Arteries to be wholly Ner∣vous.
• * 1.12

  The Arteries have a double motion, Sy∣stole and Dia∣stole.
• * 1.13

  The manner of the Pulsa∣tion of the Arteries, ac∣cording to Dr. Harvey.
• * 1.14

  The manner of the Pulsa∣tion of Arte∣ries.
• * 1.15

  The Systole of the Arte∣ries made by circular fleshy Fibres.
• * 1.16

  The current of the Blood is hastned up∣ward, espe∣cially in the Capillary Ar∣teries of the Brain.