the myocardium receives oxygenated blood from pulmonary circulation.
the myocardium receives oxygenated blood from pulmonary circulation.
where does the myocardium receives oxygenated blood from?
pulmonary circulation
there are some anastomoses between branches of the two coronary arteries. however the coronary arteries are functionally end arteries and so these meetings are referred to as potential anastomoses, which lack function, as opposed to true anastomoses like that in the palm of the hand. this is because blockage of one coronary artery generally results in death of the heart tissue due to lack of sufficient blood supply from the other branch. when two arteries or their branches join, the area of the myocardium receives dual blood supply. these junctions are called anastomoses. if one coronary artery is obstructed by an atheroma, the second artery is still able to supply oxygenated blood to the myocardium. however, this can only occur if the atheroma progresses slowly, giving the anastomoses a chance to proliferate.
coronary circulation
the african lungfishes are obligate air breathers, with reduced gills in the adults. they have two anterior gill arches that retain gills, though they are too small to function as the sole respiratory apparatus. the lungfish heart has adaptations that partially separate the flow of blood into its pulmonary and systemic circuits. the atrium is partially divided, so that the left side receives oxygenated blood and the right side receives deoxygenated blood from the other tissues. these two blood streams remain mostly separate as they flow through the ventricle leading to the gill arches. as a result, oxygenated blood mostly goes to the anterior gill arches and the deoxygenated blood mostly goes to the posterior arches.
protopterus