A very simplistic explanation:
If we start with the aorta (the biggest artery in the body), the oxygenated blood from the heart travels through this around the entire body and supplies oxygen, nutrients, etc. The deoxygenated blood then travels back to the heart via the venous systems and enters the left atrium. From the left atrium it travels to the left ventricle and is pumped by this ventricle through the pulmonary arteries (don't be deceived by the name here - the blood is still deoxygenated), to the lungs where it picks up oxygen. The oxygenated blood then travels back to the heart through the pulmonary veins and enters the right atrium. It then travels into the right ventricle and the ventricle pumps the blood into the aorta and the cycle repeats.
Essentially you have two closed loops.
Circulation of the blood
the heart is a double pump The heart pumps deoxigenated blood from the body through the heart and then through the lungs the back to the heart.
The heart pumps blood rapidly, letting it flow through the body.
The use of the valves in the heart is to have blood flow regularly through the heart. The valves pump blood out of the heart into the body.
through veins connected to the heart that lead all over the body
The haert pumps blood from the arteries and to the other parts of the body while the veins take blood into the heart.
things that could affect the blood flow through the heart
the first loop is lungs to the heart. the second loop is body to the heart.
circulation ,nervous system
The haert pumps blood from the arteries and to the other parts of the body while the veins take blood into the heart.
The left ventricle of the heart pumps blood through the aortic valve to the body. When the heart contracts, the aortic valve opens and allows oxygen-rich blood to flow from the left ventricle into the aorta, which then delivers the blood throughout the body.
Blood flows through arteries (from the heart), veins (to the heart) and capillaries. The heart pumps oxygenated blood out of the aorta and it circulates throughout the body providing oxygen to the muscles and organs (both voluntary and involuntary). The deoxygenated blood returns to the heart through veins. Veins have valves to stop blood flowing in the wrong direction. So the blood returns to the heart though both the superior and inferior vena cava and is then carried to the lungs where it is re-oxygenated, carried back to the heart and again pumped out the aorta. All in all the heart makes blood flow. A blood flow is the blood pumped from the heart to all parts of body through arteries and flow back through veins. A blood flow can also be normal menstruation, or a uterus vaginal problem.