17. The anatomy of the pulmonary circulation, topography and branches of the
pulmonary trunk.
❖ The pulmonary circulation is the portion of the circulatory system which carries
deoxygenated blood away from the right ventricle of the heart, to the lungs, and returns
oxygenated blood to the left atrium and ventricle of the heart.
❖ The term pulmonary circulation is readily paired and contrasted with the systemic
circulation.
❖ The vessels of the pulmonary circulation are the pulmonary arteries and the pulmonary
veins.
❖ 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 right atrioventricular valve, into the right ventricle.
Blood is then pumped from the right ventricle through the pulmonary valve and into the main
pulmonary artery.
❖ Pulmonary circuit carries the blood that needs to be oxygenated into the lungs where the
exchange of oxygen and carbon dioxide that the body has produced occurs before the blood
returns back to the heart.
❖ Red blood cells are responsible for oxygen binding and transportation using their hemoglobin
proteins which contain iron.
❖ Once this has happened, the heart then pumps the blood around the systemic circuit of the body
and delivers the oxygenated red blood cells to the tissues before collecting the deoxygenated
blood and sending it back to the heart with unused nutrients and waste products.
❖ Pulmonary arteries: originate from the arterial trunk, and in the developed heart, the
pulmonary trunk (main pulmonary artery) begins at the base of the right ventricle.
❖ The pulmonary trunk is a short and stout (wide) structure that is about 5 cm in length and 3 cm in
diameter, which branches into 2 pulmonary arteries; the left and right pulmonary arteries, which
act to deliver deoxygenated blood to its respective lung.
❖ On the other hand, pulmonary veins are large blood vessels that receive oxygenated blood from
the lungs to delivery to the rest of the body. There are 4 total pulmonary veins—with 2
pulmonary veins coming from each lung, left and right—that empty into the left atrium of the
heart.
❖ Two pulmonary veins emerge from the hilus of each lung, and each pulmonary vein receives
blood from 3-4 bronchial veins apiece before draining into the left atrium.
❖ The pulmonary veins are fixed to the pericardium travel alongside the pulmonary arteries .
The right superior pulmonary vein passes in front of and a tad below the pulmonary artery at
the root of the lung, and the inferior pulmonary vein is situated at the lowest part of the lung
hilum.
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pulmonary trunk.
❖ The pulmonary circulation is the portion of the circulatory system which carries
deoxygenated blood away from the right ventricle of the heart, to the lungs, and returns
oxygenated blood to the left atrium and ventricle of the heart.
❖ The term pulmonary circulation is readily paired and contrasted with the systemic
circulation.
❖ The vessels of the pulmonary circulation are the pulmonary arteries and the pulmonary
veins.
❖ 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 right atrioventricular valve, into the right ventricle.
Blood is then pumped from the right ventricle through the pulmonary valve and into the main
pulmonary artery.
❖ Pulmonary circuit carries the blood that needs to be oxygenated into the lungs where the
exchange of oxygen and carbon dioxide that the body has produced occurs before the blood
returns back to the heart.
❖ Red blood cells are responsible for oxygen binding and transportation using their hemoglobin
proteins which contain iron.
❖ Once this has happened, the heart then pumps the blood around the systemic circuit of the body
and delivers the oxygenated red blood cells to the tissues before collecting the deoxygenated
blood and sending it back to the heart with unused nutrients and waste products.
❖ Pulmonary arteries: originate from the arterial trunk, and in the developed heart, the
pulmonary trunk (main pulmonary artery) begins at the base of the right ventricle.
❖ The pulmonary trunk is a short and stout (wide) structure that is about 5 cm in length and 3 cm in
diameter, which branches into 2 pulmonary arteries; the left and right pulmonary arteries, which
act to deliver deoxygenated blood to its respective lung.
❖ On the other hand, pulmonary veins are large blood vessels that receive oxygenated blood from
the lungs to delivery to the rest of the body. There are 4 total pulmonary veins—with 2
pulmonary veins coming from each lung, left and right—that empty into the left atrium of the
heart.
❖ Two pulmonary veins emerge from the hilus of each lung, and each pulmonary vein receives
blood from 3-4 bronchial veins apiece before draining into the left atrium.
❖ The pulmonary veins are fixed to the pericardium travel alongside the pulmonary arteries .
The right superior pulmonary vein passes in front of and a tad below the pulmonary artery at
the root of the lung, and the inferior pulmonary vein is situated at the lowest part of the lung
hilum.
94
