Smallest cardiac veins contribute to normal physiologic shunting of blood. As a consequence of the input of these vessels, blood in the left heart is less oxygenated than the blood found at the pulmonary capillary beds, albeit to a very small degree. The "openings of smallest cardiac veins" are located in the endocardium. Here the smallest cardiac veins return blood into the heart chambers from the capillary bed in the muscular cardiac wall, enabling a form of collateral circulation unique to the heart. Not every endocardial opening connects to the thebesian veins as some connect to the vessels of Wearn, which are arteries.
Great arteries birth. Great arteries The great arteries are the primary arteries that carry blood away from the heart, which include: The great arteries originate from the aortic arches during embryonic development. The aortic arches start as five pairs of symmetrical vessels connecting the heart with the dorsal aorta but then undergo a significant remodelling, in which some of these vessels regress (aortic arches 1 and 2), the 3rd pair of arches contribute to form the common carotids, the right 4th will contribute to the base and central part of the right subclavian artery, while the left 4th will form the central