pump
Answer Pump blood to the lungs.
The heart has only one major function. This function is to pump blood through the body and to and from the lungs.
It carries blood from the heart to the lungs
Blood coming from the lungs has lower pressure while that from the heart has higher pressure. Blood coming from the lungs also has higher oxygen content and lower carbon dioxide content compared to that coming from the heart.
Artery - always carries blood FROM the heart Vein - always carries blood TO the heart The vein which brings blood to the heart from the lungs is the PULMONARY VEIN ('pulmonary' = lungs). The one carrying blood away from the heart to the lungs is the pulmonary artery. Easy.
The word "pulmonary" refers to the lungs, so the pulmonary vein is a blood vessel that runs from the lungs to the heart. It carries oxygenated blood, which is unusual for veins, which (apart from this one) transport de-oxygenated blood to the heart. The pulmonary artery does the opposite: unlike other arteries, it carries de-oxygenated blood from the heart to the lungs.
The pulmonary vein carries oxygen-rich blood from the lungs to the heart.
so there are veins that connect the lungs and the heart and blood vessels carry blood form any direction in and out of the pumping heart
The heart is a single organ, but it functions as a double pump sending oxygen-depleted blood to the lungs to pick-up oxygen and unload carbon dioxide, while simultaneously sending oxygen-loaded blood coming from the lungs to cells throughout the body. The heart's right ventricle pumps blood to the lungs, while the left ventricle pumps the oxygenated blood to the body cells.
The circulatory system for one needs oxygenated blood to be transported from the lungs to the heart, and it needs the body to get rid of carbon dioxide from the blood through the lungs. :)
When in the womb the fetus' lungs are not working because they do not have access to air. This means that blood does not flow down the pulmonary artery and a hole in the heart shunts the blood directly from one chamber of the heart to the other. This hole closes and the lungs begin to work after birth when the baby takes its first breath.While in the womb the baby's blood is oxygenated by the placenta which interfaces to the mother's blood supply.PLEASE NOTE: the lungs DO NOT "purify" blood. The function of the lungs is gas exchange (oxygen in - carbon dioxide out). The kidneys are the organs which remove waste products from (purify) the blood.
The heart pumps the blood that takes carbon dioxide to the lungs. So, the heart is a necessary element, but isn't the one effectively doing it.