And what brady kina does is it causes the constrictions of blood vessels when there is a high amount of oxygen. So the bradyclin essentially travels into the ductus arteriosis. And because now we have a high oxygen content within that ductus arteriosis, the brady kinan basically causes the constriction of that ductus arteriosis. And so within hours, the ductus arteriosis will essentially constrict to a point where very little blood will actually flow between the pulmonary trunk and our eight order. So, once again, following the expansion of lungs, they release a protein called bradyclin. As oxygenated blood travels through the ductus arteriosis, that protein mixes with the oxygen, with the high oxygen content, and it causes the constriction of the ductus arteriosis.