What is needed to pass oxygen from lungs into blood vessels and welcome carbon dioxide into the lungs?

Answer 1

That would be the heart. The pulmonary vein carries oxygenated blood from the lungs to the heart's left ventricle, it then travels through the left atrium and out the aorta into the arteries and then the arterioles. It then enters the capillaries, here the oxygen diffuses into the cells of the body, and carbon dioxide diffused into the capillaries and bloodstream. The blood then continues to the veinoles, veins and back into the heart through the inferior or superior vena cava, into the right ventricle, right atrium and out through the pulmonary artery to collect oxygen from the lungs again. So starting from the beginning, the diagram of blood flow is as follows:

Lungs - pulmonary vein - left ventricle - left atrium - aorta - arteries - arterioles - capillaries - veinoles - veins - superior/inferior vena cava - right ventricle - right atrium - pulmonary artery. And the cycle continues :)

Answer 2

Oxygen needs to enter the bloodstream so that the lungs can carry oxygen to all parts of the body

Answer 3

So the oxygenated blood can supply oxygen to all parts of the body from the heart

thanks

Answer 4

The scapula