World Library  
Flag as Inappropriate
Email this Article

Pulmonary circulation

Article Id: WHEBN0000598465
Reproduction Date:

Title: Pulmonary circulation  
Author: World Heritage Encyclopedia
Language: English
Subject: Michael Servetus, Respiratory physiology, Circulatory system, Heart, Fossa ovalis (heart)
Collection: Angiology, Respiratory Physiology, Underwater Diving Physiology
Publisher: World Heritage Encyclopedia

Pulmonary circulation

Diagram of pulmonary circulation. Oxygen-rich blood is shown in red; oxygen-depleted blood in blue.

Pulmonary circulation is the portion of the cardiovascular system which carries deoxygenated blood away from the heart, to the lungs, and returns oxygenated (oxygen-rich) blood back to the heart. The term pulmonary circulation is readily paired and contrasted with the systemic circulation. A separate system known as the bronchial circulation supplies blood to the tissue of the larger airways of the lung.


  • Route 1
    • Arteries 1.1
    • Lungs 1.2
    • Veins 1.3
  • History 2
  • Embryonic 3
  • See also 4
  • External links 5
  • References 6


Pulmonary circulation is the movement of blood from the heart, to the lungs, and back to the heart again. Deoxygenated blood leaves the heart, goes to the lungs, and then re-enters the heart; Deoxygenated blood leaves through the right ventricle through the pulmonary artery. From the right atrium, the blood is pumped through the tricuspid valve (or right atrioventricular valve), into the right ventricle. Blood is then pumped from the right ventricle through the pulmonary valve and into the pulmonary trunk of the pulmonary artery.


From the right ventricle, blood is pumped through the pulmonary semi-lunar valve into the left and right pulmonary arteries (one for each lung) and travels through the lungs.


The pulmonary arteries carry deoxygenated blood to the lungs, where it releases carbon dioxide and picks up oxygen during respiration. Arteries are further divided in to very fine branches called the capillaries. In structure the capillaries are very thin walled. Their function is to assist in the carrying of blood to all cells of the body. The pulmonary vein returns oxygenated blood to the left atrium of the heart.


The oxygenated blood then leaves the lungs through pulmonary veins, which return it to the left heart, completing the pulmonary cycle. This blood then enters the left atrium, which pumps it through the bicuspid valve, also called the mitral or left atrioventricular valve, into the left ventricle. From the left ventricle the blood passes through the aortic valve to the aorta. The blood is then distributed to the body through the systemic circulation before returning again to the pulmonary circulation.


Pulmonary circulation was first described by Ibn al-Nafis in his Commentary on Anatomy in Avicenna's Canon (1242). Ibn al-Nafis described pulmonary circulation as:[1][2]

"the blood from the right chamber of the heart must arrive at the left chamber but there is no direct pathway between them. The thick septum of the heart is not perforated and does not have visible pores as some people thought or invisible pores as Galen thought. The blood from the right chamber must flow through the vena arteriosa (pulmonary artery) to the lungs, spread through its substances, be mingled there with air, pass through the arteria venosa (pulmonary vein) to reach the left chamber of the heart and there form the vital spirit..."

It was later described by Michael Servetus in the "Manuscript of Paris"[3] (near 1546, never published) and later published in his Christianismi Restitutio (1553). Since it was a theology work condemned by most of the Christian factions of his time, the discovery remained mostly unknown until the dissections of William Harvey in 1616.


The pulmonary circulation loop is virtually bypassed in fetal circulation. The fetal lungs are collapsed, and blood passes from the right atrium directly into the left atrium through the foramen ovale: an open conduit between the paired atria, or the ductus arteriosus: a shunt between the pulmonary artery and the aorta. When the lungs expand at birth, the pulmonary pressure drops and blood is drawn from the right atrium into the right ventricle and through the pulmonary circuit. Over the course of several months, the foramen ovale closes, leaving a shallow depression known as the fossa ovalis in the adult heart.

See also

External links

  • Official Journal of the Pulmonary Vascular Research Institute
  • Michael Servetus Research Study on the Manuscript of Paris with the description of the Pulmonary Circulation, and more works by Servetus.


  1. ^ The Pursuit of Learning in the Islamic World, 610-2003 By Hunt Janin, Pg99
  2. ^ Saints and saviours of Islam, By Hamid Naseem Rafiabadi, Pg295
  3. ^ 2011 “The love for truth. Life and work of Michael Servetus”, (El amor a la verdad. Vida y obra de Miguel Servet.), printed by Navarro y Navarro, Zaragoza, collaboration with the Government of Navarra, Department of Institutional Relations and Education of the Government of Navarra, 607 pp, 64 of them illustrations, p 215-228 & 62nd illustration (XLVII)
This article was sourced from Creative Commons Attribution-ShareAlike License; additional terms may apply. World Heritage Encyclopedia content is assembled from numerous content providers, Open Access Publishing, and in compliance with The Fair Access to Science and Technology Research Act (FASTR), Wikimedia Foundation, Inc., Public Library of Science, The Encyclopedia of Life, Open Book Publishers (OBP), PubMed, U.S. National Library of Medicine, National Center for Biotechnology Information, U.S. National Library of Medicine, National Institutes of Health (NIH), U.S. Department of Health & Human Services, and, which sources content from all federal, state, local, tribal, and territorial government publication portals (.gov, .mil, .edu). Funding for and content contributors is made possible from the U.S. Congress, E-Government Act of 2002.
Crowd sourced content that is contributed to World Heritage Encyclopedia is peer reviewed and edited by our editorial staff to ensure quality scholarly research articles.
By using this site, you agree to the Terms of Use and Privacy Policy. World Heritage Encyclopedia™ is a registered trademark of the World Public Library Association, a non-profit organization.

Copyright © World Library Foundation. All rights reserved. eBooks from Project Gutenberg are sponsored by the World Library Foundation,
a 501c(4) Member's Support Non-Profit Organization, and is NOT affiliated with any governmental agency or department.