The beginning of the blood's journey through the body happens when the heart relaxes between beats and the blood flows from the atria to the ventricles from where the blood is pushedÂ into the large arteries and thenÂ on to the smaller arteries where it releases oxygen and nutrients. The blood, nowÂ low on oxygen, gets pushed into the veins and travels back to the heart.Â Once the blood goes back to the heart, it is oxygenated and the process begins again.
Each heart beat begins a new cycle of circulation and pushes blood through the body. Circulation begins in the right ventricle, and this is where oxygen-poor blood is released, causing people to breathe out the carbon dioxide that is picked up along the way. As the blood travels through the pulmonary vein into the left atrium and left ventricle, oxygen is pumped into the blood.
The heart is a strong muscle and is about the size of a fist. It is located in the middle of the chest, slightly to the left, and the right side of the heart pumps blood to the lungs while the left side receives oxygen-poor blood. Each side of the heart beats at different times while performing its function.