The Circulation of the Blood in the Cardiovascular System

‘I began privately to think that it might rather have a certain movement, as it were, in a circle, which I afterwards found to be true’.

William Harvey, Exercitatio Anatomica De Motu Cordis et Sanguinis in Animalibus (Frankfurt, 1628), p. 41 (translation by Don. G. Bates).[1]

According to the second-century AD physician Galen of Pergamon, the origin of blood lay in the liver, where it was concocted from digested food. It then flowed centrifugally to the peripheries, where it was absorbed, and so, instead of a circulatory system, the liver had to continuously replenish blood. This Galenic system, which had dominated medieval and early modern medicine, was to be completely undermined by the work of William Harvey (1578–1657), ‘arguably the most important cardiovascular investigator of all time’.[2] In his seminal work Exercitatio Anatomica De Motu Cordis et Sanguinis in Animalibus (Frankfurt, 1628), Harvey demonstrated the circulation of the blood in the cardiovascular system.

Daniel Le Clerc and Jean Jacques Manget, Bibliotheca anatomica sive Recens in anatomia inventorum thesaurus locupletissimus (Geneva, 1685), ii, Tab XXXIX (detail of Figs. 1-4), demonstrating William Harvey’s experiment on the circulation of the blood.

Edward Worth did not own a separate edition of Harvey’s Exercitatio Anatomica De Motu Cordis et Sanguinis in Animalibus (Frankfurt, 1628), but its principal findings were included in his copy of the second volume of Daniel Le Clerc’s and Jean Jacques Manget’s, Bibliotheca anatomica sive Recens in anatomia inventorum thesaurus locupletissimus (Geneva, 1685).[3] Harvey had been educated at the University of Cambridge before travelling to Padua, where he was awarded his MD in 1602. His experience there of the teaching of Fabricius of Acquapendente (1533–1619), and in particular the latter’s description of the valves in the veins, was to have a major influence on his work. On his return to England, he began to practice medicine and was admitted to the College Physicians in 1604. By 1615 he was so highly thought of that he was asked to give the College’s Lumleian lecture series, and, as French notes, the seeds of Exercitatio Anatomica De Motu Cordis et Sanguinis in Animalibus may be seen in the lectures he gave as part of this series from 1616 onwards.

Harvey’s Exercitatio Anatomica De Motu Cordis et Sanguinis in Animalibus examined the movement of the heart and the direction of the flow of the blood. The above image depicts his famous experiment, proving that venous blood slows centripetally toward the heart. By using tourniquets on the arms of muscular farm workers (whose veins were more clearly seen), he examined the flow of blood, noting that it did not flow to the peripheries (as Galen suggested), but rather flowed to the heart. Harvey’s experimental method and his emphasis on quantitative evidence – for example, he queried how much blood the liver would have to produce daily for the Galenic model to be true – let him to question the Galenic model of two distinct networks of arteries and veins and instead propose a unified cardiovascular system.

Harvey outlined his process of deduction in chapter 8 of Exercitatio Anatomica De Motu Cordis et Sanguinis in Animalibus:

‘In truth, when, from a variety of investigations through dissection of the living in order to experiment and through the opening of arteries, from the symmetry and magnitude of the ventricles of the heart and of the vessels entering and leaving (since Nature, who does nothing in vain, would not have needlessly given these vessels such relatively large size), from the skilful and careful craftsmanship of the valves and fibres and the rest of the fabric of the heart, and from many other things, I had very often and seriously thought about, and had long turned over in my mind, how great an amount there was, that is to say how great the amount of transmitted blood would be [and] in how short a time that transmission would be effected, and [when] I [then] became aware that the juice of the ingested aliment could not have sufficed without our having the veins emptied, utterly drained, and the arteries on the other hand burst asunder by the too great inthrust of blood, unless the blood were somewhere to return again from the arteries into the veins and to go back to the right ventricle of the heart, I began privately to think that it might rather have a certain movement, as it were, in a circle, which I afterwards found to be true, and that the blood is thrust out from the heart through the arteries, and driven forward into the habit of the body and to all parts, by the beat of the left ventricle of the heart, just as [the blood is thrust out] by the [beat of the] right [ventricle] into the lungs through the arterial vein; and returns back again through the veins into the vena cava and up to the right auricle, just as [the blood returns] from the lungs through the so-called venous artery to the left ventricle, as was previously said’.[4]

Nathaniel Highmore, Corporis humani disquisitio anatomica in qua sanguinis circulationem in quavis corporis particula plurimis typis novis ac ænygmatum medicorum succincta dilucidatione ornatam prosequutus est Nathanael Highmorus (The Hague, 1651), engraved title page.

Harvey’s theory of the circulation of the blood was radical and it earned him many detractors, not least because it undermined the rationale for much contemporary medical practice. Among the most vociferous of his opponents was Jean Riolan the Younger (1580–1657), a professor at the University of Paris, but Harvey also had a number of loyal supporters and among the latter was Nathaniel Highmore (1613–85). Highmore, after gaining his BM in 1641 at the University of Oxford, had, throughout the 1640s, become part of a scientific circle which included Harvey. It was to Harvey that Highmore dedicated his textbook Corporis humani disquisitio anatomica (The Hague, 1651), and the book sought to popularize Harvey’s theory of the circulation of the blood while at the same time answer Harvey’s critics. As Ekholm notes, its significance lies in the fact that it was ‘among the first comprehensive human anatomy books to describe the parts of the body in the light of Harvey’s discovery’ and in a fascinating article she rightly points to the many ways in which Highmore went beyond even Harvey in his discussion of the circulation of the blood, in particular in his focus on the heart as a pump.[5]

Highmore draws attention to this in the above engraved title page of the work which depicts the skin of the two-headed Janus being stretched between the ancient authorities of Hippocrates and Galen, with Queen Anatomy seated in a temple at its head. On the right of Queen Anatomy is the scholar in his chamber, closed off from discovery by relying too heavily on the ancients – unlike Highmore, who is depicted kneeling to the Queen on the left, offering her the fruits of his research, research which, as is clear, is the result of actual dissection.  Of particular note is the section beneath the legs of Janus, which is described in Highmore’s accompanying explanatory verse as follows:

‘The artery, here like a cistern fixed to the Caucasus,

expels its waterfall of blood

and rose Maeanders to irrigate the Asia Minor of man,

and distant provinces of the soul.

With the course having been completed up to this point,

the streams press out their beds into the large vein,

the dark red Danube of man,

to revolve by perpetually falling,

 and again to kiss the stained ocean with the purple dye of the liver,

and to restore the vivifying heat from the pump’ (lines 48–57).[6]

As Ekholm notes, the imagery in the engraved title page is complex, and harks back to both classical themes and contemporary models, such as the title page of Adriaan van den Spieghel’s De Fabrica, which Worth owned in a 1645 Amsterdam edition of the latter’s works. An image of the title page may be found in the ‘Padua’ section of this online exhibition for Van den Spieghel (1578–1625), had succeeded Giulio Cesare Casseri (fl., 1552–1616), as professor of anatomy at the University of Padua during the seventeenth century. Highmore’s homage was not slavish – he was more than prepared to criticise Van den Spiegel on numerous points. In addition, he added in other anatomical discoveries of his own, not least his work on the maxillary sinus of the nose.

Kaspar Bauhin, Theatrum anatomicum (Frankfurt, 1621), Tabula IV, view from the rear, depicting cutaneous veins.

As Aird notes, in the Galenic system, there were two distinct networks of arteries and veins, with a suggested cross over via invisible pores in the interventricular septum and peripheral anastomoses.[7] Galen’s system had been heavily influenced by the ancient Greek school of Cos: Praxagoras of Cos (340 BC) had argued that arteries began in the heart and veins in the liver and that while the veins carried blood, the arteries carried pneuma.[8]  Erasistratus of Cos (3^rd century BC) agreed but suggested that the heart was the source of both. Galen, in his turn, noted differences between arteries and veins – both in their location and in the blood they contained. He argued that while both arteries and veins contained blood, the arteries also carried pneuma, and postulated that venous blood permeated invisible pores in the interventricular septum. The existence of these invisible pores was questioned by Vesalius in 1543 but it was Harvey’s conclusion that the arteries and veins contained the same blood and his explanation of how this was so which fundamentally undermined the Galenic system.

Lorenz Heister, L’Anatomie d’Heister avec des essais de physique sur l’usage des parties du corps humain, et sur le méchanisme de leurs mouvemens (Paris, 1724), Plate XIII: arteries in the arm and leg.

One problem that Harvey could not solve was the question of the how blood moved from arteries to veins. As Bolli notes, Harvey postulated the existence of pores in tissues but it was a problem that awaited the microscopic investigations of Marcello Malpighi (1628–94), who in 1661 discovered capillaries.[9]

Text: Dr Elizabethanne Boran, Librarian of the Edward Worth Library, Dublin.

Sources

Aird, W.C., ‘Discovery of the cardiovascular system: from Galen to William Harvey’, Journal of Thrombosis and Haemostasis, 9 Supplement 1 (2011), 118–29.

Bates, D.G., ‘Harvey’s account of his ‘discovery’’, Medical History, 36 (1992), 361–78.

Bolli, Roberto, ‘William Harvey and the Discovery of the Circulation of the Blood, Part I’, Circulation Research, 124, no. 8 (2019), 1169–1171.

Bolli, Roberto, ‘William Harvey and the Discovery of the Circulation of the Blood, Part II’, Circulation Research, 124, no. 9 (2019), 1300–1302.

Bolli, Roberto, ‘William Harvey and the Discovery of the Circulation of the Blood, Part III’, Circulation Research, 124, no. 10 (2019), 1428–9.

Boylan, Michael, ‘Galen: On Blood, the Pulse, and the Arteries’, Journal of the History of Biology, 40, no. 2 (2007), 207–30.

Ekholm, Karin, ‘Anatomy, Bloodletting and Emblems: interpreting the Title-Page of Nathaniel Highmore’s Disquisitio (1651),’, Early Science and Medicine, 18, nos. 1-2 (2013), 87–123.

French, Roger, ‘Harvey, William (1578–1657), physician and discoverer of the circulation of the blood, ODNB, 2004.

Loukas, Marios, et al, ‘History of Cardiac Anatomy: A Comprehensive Review from the Egyptians to Today’, Clinical Anatomy, 29 (2016), 270–84.

Oster, Malcolm, ‘Highmore, Nathaniel (1613–1685), chemical physician and anatomist, ODNB.

Pearse, J.M.S, ‘Malpighi and the discovery of capillaries’, European Neurology, 58 (2007), 253–5.

Persaud, T.V.N., A History of Anatomy. The Post-Vesalian Era (Springfield, 1997).

Prendergast, J., ‘Galen’s View of the Vascular System in Relation to that of Harvey’, Journal of the Royal Society of Medicine, 21, no. 12 (1928), 1839–48.

[1] English translation by Don G. Bates in ‘Harvey’s account of his ‘discovery’’, Medical History, 36 (1992), 364.

[2] Bolli, Roberto, ‘William Harvey and the Discovery of the Circulation of the Blood, Part I’, Circulation Research, 124, no. 8 (2019), 1169.

[3] Worth did, however, own not one but two editions of Harvey’s Exercitationes de generatione animalium (Amsterdam, 1674 and The Hague, 1680).

[4] English translation by Don G. Bates in his illuminating article on ‘Harvey’s account of his ‘discovery’’, Medical History, 36 (1992), 364.

[5] Ekholm, Karin, ‘Anatomy, Bloodletting and Emblems: interpreting the Title-Page of Nathaniel Highmore’s Disquisitio (1651),’, Early Science and Medicine, 18, nos 1-2 (2013), 92.

[6] English translation by Karin Ekholm in Ekholm, Karin, ‘Anatomy, Bloodletting and Emblems: interpreting the Title-Page of Nathaniel Highmore’s Disquisitio (1651)’, 107.

[7] On ancient theories see Aird, W.C., ‘Discovery of the cardiovascular system: from Galen to William Harvey’, Journal of Thrombosis and Haemostasis, 9 Supplement 1 (2011), 1198–29 and Boylan, Michael, ‘Galen: On Blood, the Pulse, and the Arteries’, Journal of the History of Biology, 40, no. 2 (2007), 207–30.

[8] Boylan, Michael, ‘Galen: On Blood, the Pulse, and the Arteries’,, 215.

[9] Bolli, Roberto, ‘William Harvey and the Discovery of the Circulation of the Blood, Part III’, Circulation Research, 124, no. 10 (2019), 1428. See also Pearse, J.M.S, ‘Malpighi and the discovery of capillaries’, European Neurology, 58 (2007), 253–5.