CHAP. V.Of theHeartofQuadrupeds.
Of theHeartofQuadrupeds.
In this Part there is a notable Difference found between the Heart of Man and that of Beasts, concerning the latter, of which I might take notice of the remarkable Confirmation of the Hearts of AmphibiousQuadrupeds, and their Difference from those of Land-Animals, some having but one Ventricle[a], some three[b], and some but two (like Land-Animals) but then theForamen Ovaletherewith[c]. All which may be justly esteemedas wonderful, as they are excellent Provisions for the Manner of those Animals living. But I shall content my self with bare Hints of these Things, and speak only of two Peculiars more, and that but briefly.
One is the Situation of the Heart, which in Beasts is near the middle of the whole Body; in Man, nearer the Head[d]. The Reasons of which I shall give from one of the most curious Anatomists of that Part[e]. “Seeing, saith he, the Trajection and Distribution of the Blood depends wholly on the Systole of the Heart, and that its Liquor is not driven of its own Nature so readily into the upper Parts as into Vessels even with it, or downwards into those under it: If the Situation of the Heart had been further from the Head, it must needs either have been made stronger to cast out its Liquor with greater Force; or else the Head would want its due Proportion of Blood. But in Animals that have a longer Neck, and which is extended towards their Food as it were, the Heart is seated as far from the other Parts; and they find no Inconvenience from it, because they feed with their Head for the most part hanging down; and so the Blood, as it hath farther to go to their Head than in others, so it goes a plainer and often a steep Way[f].”
The other peculiar Matter is, the fastning (I formerly mentioned) which the Cone of thePericardiumhath in Man to theDiaphragm[g], whereas in allQuadrupedsit is loose. By which Means the Motion of theMidriff, in that necessary Act of Respiration, is assisted both in the upright Posture of Man, as also in the prone Posture ofQuadrupeds[h]; which would be hindred, or rendred more difficult, if the Case was otherwise: “Which must needs be the Effect of Wisdom and Design, and that Man was intended by Nature to walk erect, and not upon all-four, asQuadrupedsdo:” To express it in the Words of a great Judge in such Matters[i].
FOOTNOTES:[a]Frogsare generally thought to have but one Ventricle in their Hearts.[b]TheTortoisehath three Ventricles, as theParisian Academistsin theirMemoirsaffirm.Besides these two Ventricles[before spoken of]which were in the hinder Part of the Heart, which faceth the Spine; there was, say they,a third in the Fore-part, inclining a little towards the Right-side,&c.Memoirs,&c.p. 259. But Mr.Bussierecharges this as a Mistake in those ingenious Gentlemen, and asserts there is but one Ventricle in theTortoise’s Heart. See his Description of the Heart of theLand Tortoise, inPhilos. Transact.Nᵒ. 328.[c]TheSea-Calfis said by theFrench Academists, to have this Provision, and their Account of it is this:Its Heart was round and flat. Its Ventricles appeared very large, and its Auricles small.——Underneath the great Aperture, through which the Trunk of theVena Cavaconveyed the Blood into the right Ventricle of the Heart, there was another, which penetrated into theArteria Venosa, and from thence into the left Ventricle, and afterwards into theAorta. This Hole called theForamen Ovalein theFœtus, make theAnastomisis, by the Means of which, the Blood goes from theCavainto theAorta, without passing through the Lungs.French Anatomists, p. 124.[d]Τὴν τε Καρδίαν περὶ τὸ μέσον πλὴν ἐν ἀνθρώπῳ, &c. Arist. Hist. An. L. 2. c. 17.[e]Dr.Lower,de Corde, c. 1.[f]I might have mentioned another wise Provision from the same Author, which take in his own Words:In Vitulu & Equis, imò plerique aliis animalibus majoribus, non solas propagines à Nervo sexti paris ut in Homine, sed etiam plurimas à Nervo intercostali, ubi rectà cor transit, cor accedere, imò in parenchyma ejus dimitti: & hoc ideo à Naturâ quasi subsidium Brutis comparatum, ne capita quæ terram prona spectant, non satis facilè aut copiosè Spiritus Animales impertirent.Blasii Anat. Animal. Par. 1. c. 4. ex Lowero. de Corde.[g]Diaphragmatis circulo nerveo firmiter adheret[Pericardium]quod Homini singulare; nam ab eo in Canibus & Simiis distat, item in aliis animalibus omnibus.Bartholm. Anat. L. 2. c. 5.[h]Finalem causam quod atrinet,——cùm erectus sit Hominis incessus atque figura, eoque facilius abdominis viscera suo pondere descendant, minore Diaphragmatis nixu atque Systole ad Inspirationem opus est; porro, cùm in Exspiratione pariter necessarium sit Diaphragma relaxari,——cùm capsula cordis omnino connectendum fuit, in Homine, ne fortè, quamdiu erectus incedit, ab Hepatis aliorumque viscerum appensorum pondere deorsum adeò deprimeretur, ut neque Pulmo satis concidere, neque Expiratio debito modo peragi potuerit. Quocirea in Quadrupedibus, ubi abdominis viscera in ipsum Diaphragma incumbunt, ipsumque in pectoris cavitatem suo pondere impellant, ista partium accretio Exspirationi quidem inutilis, Inspirationi autem debitam Diaphragmatis tensionem impediendo, prorsus incommoda fuisset.Lower, ib. p. 8.[i]Dr.Tyson’s Anat. of the Orang-Outang, inRay’s Wisd. of God, p. 262.
[a]Frogsare generally thought to have but one Ventricle in their Hearts.
[a]Frogsare generally thought to have but one Ventricle in their Hearts.
[b]TheTortoisehath three Ventricles, as theParisian Academistsin theirMemoirsaffirm.Besides these two Ventricles[before spoken of]which were in the hinder Part of the Heart, which faceth the Spine; there was, say they,a third in the Fore-part, inclining a little towards the Right-side,&c.Memoirs,&c.p. 259. But Mr.Bussierecharges this as a Mistake in those ingenious Gentlemen, and asserts there is but one Ventricle in theTortoise’s Heart. See his Description of the Heart of theLand Tortoise, inPhilos. Transact.Nᵒ. 328.
[b]TheTortoisehath three Ventricles, as theParisian Academistsin theirMemoirsaffirm.Besides these two Ventricles[before spoken of]which were in the hinder Part of the Heart, which faceth the Spine; there was, say they,a third in the Fore-part, inclining a little towards the Right-side,&c.Memoirs,&c.p. 259. But Mr.Bussierecharges this as a Mistake in those ingenious Gentlemen, and asserts there is but one Ventricle in theTortoise’s Heart. See his Description of the Heart of theLand Tortoise, inPhilos. Transact.Nᵒ. 328.
[c]TheSea-Calfis said by theFrench Academists, to have this Provision, and their Account of it is this:Its Heart was round and flat. Its Ventricles appeared very large, and its Auricles small.——Underneath the great Aperture, through which the Trunk of theVena Cavaconveyed the Blood into the right Ventricle of the Heart, there was another, which penetrated into theArteria Venosa, and from thence into the left Ventricle, and afterwards into theAorta. This Hole called theForamen Ovalein theFœtus, make theAnastomisis, by the Means of which, the Blood goes from theCavainto theAorta, without passing through the Lungs.French Anatomists, p. 124.
[c]TheSea-Calfis said by theFrench Academists, to have this Provision, and their Account of it is this:Its Heart was round and flat. Its Ventricles appeared very large, and its Auricles small.——Underneath the great Aperture, through which the Trunk of theVena Cavaconveyed the Blood into the right Ventricle of the Heart, there was another, which penetrated into theArteria Venosa, and from thence into the left Ventricle, and afterwards into theAorta. This Hole called theForamen Ovalein theFœtus, make theAnastomisis, by the Means of which, the Blood goes from theCavainto theAorta, without passing through the Lungs.French Anatomists, p. 124.
[d]Τὴν τε Καρδίαν περὶ τὸ μέσον πλὴν ἐν ἀνθρώπῳ, &c. Arist. Hist. An. L. 2. c. 17.
[d]Τὴν τε Καρδίαν περὶ τὸ μέσον πλὴν ἐν ἀνθρώπῳ, &c. Arist. Hist. An. L. 2. c. 17.
[e]Dr.Lower,de Corde, c. 1.
[e]Dr.Lower,de Corde, c. 1.
[f]I might have mentioned another wise Provision from the same Author, which take in his own Words:In Vitulu & Equis, imò plerique aliis animalibus majoribus, non solas propagines à Nervo sexti paris ut in Homine, sed etiam plurimas à Nervo intercostali, ubi rectà cor transit, cor accedere, imò in parenchyma ejus dimitti: & hoc ideo à Naturâ quasi subsidium Brutis comparatum, ne capita quæ terram prona spectant, non satis facilè aut copiosè Spiritus Animales impertirent.Blasii Anat. Animal. Par. 1. c. 4. ex Lowero. de Corde.
[f]I might have mentioned another wise Provision from the same Author, which take in his own Words:In Vitulu & Equis, imò plerique aliis animalibus majoribus, non solas propagines à Nervo sexti paris ut in Homine, sed etiam plurimas à Nervo intercostali, ubi rectà cor transit, cor accedere, imò in parenchyma ejus dimitti: & hoc ideo à Naturâ quasi subsidium Brutis comparatum, ne capita quæ terram prona spectant, non satis facilè aut copiosè Spiritus Animales impertirent.Blasii Anat. Animal. Par. 1. c. 4. ex Lowero. de Corde.
[g]Diaphragmatis circulo nerveo firmiter adheret[Pericardium]quod Homini singulare; nam ab eo in Canibus & Simiis distat, item in aliis animalibus omnibus.Bartholm. Anat. L. 2. c. 5.
[g]Diaphragmatis circulo nerveo firmiter adheret[Pericardium]quod Homini singulare; nam ab eo in Canibus & Simiis distat, item in aliis animalibus omnibus.Bartholm. Anat. L. 2. c. 5.
[h]Finalem causam quod atrinet,——cùm erectus sit Hominis incessus atque figura, eoque facilius abdominis viscera suo pondere descendant, minore Diaphragmatis nixu atque Systole ad Inspirationem opus est; porro, cùm in Exspiratione pariter necessarium sit Diaphragma relaxari,——cùm capsula cordis omnino connectendum fuit, in Homine, ne fortè, quamdiu erectus incedit, ab Hepatis aliorumque viscerum appensorum pondere deorsum adeò deprimeretur, ut neque Pulmo satis concidere, neque Expiratio debito modo peragi potuerit. Quocirea in Quadrupedibus, ubi abdominis viscera in ipsum Diaphragma incumbunt, ipsumque in pectoris cavitatem suo pondere impellant, ista partium accretio Exspirationi quidem inutilis, Inspirationi autem debitam Diaphragmatis tensionem impediendo, prorsus incommoda fuisset.Lower, ib. p. 8.
[h]Finalem causam quod atrinet,——cùm erectus sit Hominis incessus atque figura, eoque facilius abdominis viscera suo pondere descendant, minore Diaphragmatis nixu atque Systole ad Inspirationem opus est; porro, cùm in Exspiratione pariter necessarium sit Diaphragma relaxari,——cùm capsula cordis omnino connectendum fuit, in Homine, ne fortè, quamdiu erectus incedit, ab Hepatis aliorumque viscerum appensorum pondere deorsum adeò deprimeretur, ut neque Pulmo satis concidere, neque Expiratio debito modo peragi potuerit. Quocirea in Quadrupedibus, ubi abdominis viscera in ipsum Diaphragma incumbunt, ipsumque in pectoris cavitatem suo pondere impellant, ista partium accretio Exspirationi quidem inutilis, Inspirationi autem debitam Diaphragmatis tensionem impediendo, prorsus incommoda fuisset.Lower, ib. p. 8.
[i]Dr.Tyson’s Anat. of the Orang-Outang, inRay’s Wisd. of God, p. 262.
[i]Dr.Tyson’s Anat. of the Orang-Outang, inRay’s Wisd. of God, p. 262.