How does blood travel from the right atrium back to the right atrium?
blood enters the right atrium from the inferior vena cava and the superior vena cava.(they collect the de-oxygenated blood from the lower and upper part of the body respectively).
They pour all the blood in the right atrium.
from the right atrium the blood is poured into the right ventricle through the tricuspid valve.
The right ventricle pumps the blood into the pulmonary artery.
the pulmonary artery divides into two.
Right and left pulmonary artery ,going to the right and the left lung respectively.
note:this is the only artery with carries de-oxygenated blood.
the blood gets oxygenated in the lungs,and now is rich in oxygen.
the blood returns to the heart through pulmonary veins.
(note:They are the only veins that carry oxygenated blood.)
and the blood is poured into the left atrium from which it passes through the bicuspid valve or the mitral valve into the left ventricle.
the left ventricle now pumps the blood into the aorta through the aortic valve .
(note- the wall of the left ventricle is thicker then the wall of the right ventricle and the blood needs to pushed with greater force in the
aorta as it is beings carried a larger distance in the aorta.)
Aorta branches into many arteries and travels the whole length of the body providing the body with oxygen.
the smallest of the arteries are the arterioles and they are just made of a single layer of cells which provide oxygen to the body cells.
these arterioles on there way through a part or organ of the body become de oxygenated and on leaving the organ join again to form veins and veins join to form the superior or inferior vena cava respectively. Carrying the blood to the right atrium.