[Music] this video is part of the circulatory system where we discuss what is meant by double circulation and the systemic and pulmonary circuits so how blood is pumped around the body the pathways so what is meant by double circulation this means that the blood passes through the heart twice so the heart is acting really like two pumps in one one side of the heart the right side is pumping deoxygenated blood to the lungs and the other side the left side is pumping oxygenated blood to the body all at the same time this double circulation involves two circuits the pulmonary circuit and the systemic circuit so let's go through the pulmonary circuit where the blood is pumped from the heart to the lungs back to the heart again so deoxygenated blood is pumped out of the right ventricle leaves the heart in the pulmonary artery and is delivered to the lungs where it's re-oxygenated this re-oxygenated blood is delivered back to the heart in the pulmonary vein so in the pulmonary circuit the blood is pumped a relatively short distance from the heart to the lungs back to the heart again and that's why the right ventricle wall is not as thick as the left ventricle wall the systemic circuit is all about pumping blood from the heart all over the body and back to the heart again so the systemic circuit begins at the left ventricle where blood is pumped out of the left ventricle and leaves the heart in the aorta so it's carried away in that large artery this oxygenated blood is then delivered to all areas of the body becomes deoxygenated and is returned in the vena cava to the right atrium the systemic circuit involves pumping the blood quite a long distance from the heart to all areas of the body and back to the heart again and that's why the wall of the left ventricle is that much thicker than the right so what are the benefits of double circulation firstly oxygenated and deoxygenated blood is separated and pumped separately which is much more efficient and this also facilitates higher blood pressure and this higher blood pressure is needed to ensure blood reaches all parts of the body so that was double circulation you never know it might make an appearance on your exam this year and it's those small details and chapters that sometimes can catch you out remember always use your textbook always do past papers and listen to your teacher and the icons used in this project are from the noun project i'm a pro member but i still wish to give credit