The structure of the heart, the large and small circuit

The heart is located in the chest, usually behind the left lung. But with some exceptions, people have their heart set on it
opposite side.

We have left and right halves of the heart. where each of the halves has 2 chambers each, Atrium
and Main chamber (4 chambers in total) These are separated by means of two thin flaps that open
to close for the passage of blood. (these valves are one-way operated so the blood can only pump
one way, this leads to us not being able to pump e.g. oxygen-poor blood back to the big one
the circuit.)

We also have 2 circuits in the body which are controlled by these 2 halves of the heart. These are discussed
such as the Small circuit (right side) and the Large circuit (left side).

The Great Circulation (Systemic Circulation) pumps oxygen-rich blood out into the body, when this
the blood is pumped out, O2 is exchanged for the "waste substance" Co2 (oxygen-poor blood) then
the oxygen-poor blood is transported back to the atrium of the heart, pumped through
main chamber and out into the small circuit where Co2 is excreted in the lungs and then breathed out, new
air is inhaled and O2 is taken back into the bloodstream via the alveoli. After this, O2-
rich blood pumped into the heart again also starts the whole process again.