Path
The pulmonary veins carry oxygenated blood from the lungs to the left atrium of the heart. In humans there are normally four pulmonary veins, two from each lung. As part of the pulmonary circulation they carry oxygenated blood back to the heart, as opposed to the veins of the systemic circulation which carry deoxygenated blood.
Occasionally the three veins on the right side remain separate, and not infrequently the two left pulmonary veins end by a common opening into the left atrium. Therefore, the number of pulmonary veins opening into the left atrium can vary between three and five in the healthy population.
The right pulmonary veins pass behind the right atrium and superior vena cava; the left in front of the descending thoracic aorta. At the root of the lung, the superior pulmonary vein lies in front of and a little below the pulmonary artery; the inferior is situated at the lowest part of the hilus of the lung and on a plane posterior to the upper vein. Behind the pulmonary artery is the bronchus. Within the pericardium, their anterior surfaces are invested by the serous layer of this membrane.
Read more about this topic: Pulmonary Vein
Famous quotes containing the word path:
“They take abuse
with smiles,
their hardship
with great ceremony,
their quarrels
with tears:
This is the path of good women.”
—Hla Stavhana (c. 50 A.D.)
“Imagination places the future world for us either above or below or in reincarnation. We dream of travels throughout the universe: is not the universe within us? We do not know the depths of our spirit. M The mysterious path leads within. In us, or nowhere, lies eternity with its worlds, the past and the future.”
—Novalis [Friedrich Von Hardenberg] (1772–1801)
“Whoever heeds instruction is on the path to life, but one who rejects a rebuke goes astray.”
—Bible: Hebrew, Proverbs 10:17.