The heart is such an amazing organ in the body. It is located in the mediastinum, which includes everything located between the lungs is the ventral cavity. The heart is basically two pumps, one on the right and left side, that makes up one organ. The right side of the heart does less work than the left side of the heart, which correlates to the right side of the heart having less muscle and pressure. The left side of the heart is associated with high pressure and muscle mass because it performs systemic circulation.

Systemic circulation is defined as blood pumped from the heart to the rest of the body. The right side of the heart is in charge of pulmonary circulation. Pulmonary circulation is when blood is pumped to the lungs and then back to the heart. Pulmonary circulation carries deoxygenated blood until it reaches the capillaries of the lungs. .

First, deoxygenated blood (blue in diagram) enters the right atrium through the cranial and caudal vena cava veins. If needed, there is a right auricle that can allow more blood to be pumped by expanding the total volume that can enter the right atrium. Next, blood will get transferred to the right ventral of the heart via the right atrioventricular valve. The right atrioventricular valve is pulled shut by chordae tendineae which is connected to papillary muscles. The papillary muscles pull on the chordae tendineae when it contracts in efforts to prevent prolapse from occurring. The deoxygenated blood, then passes through the pulmonary valve to reach the pulmonary trunk. The pulmonary valve will be closed when the pressure is lower and blood pools and will be open when the pressure is high and the heart is pumping out blood. Further, the blood flow continues from the pulmonary trunk to the pulmonary arteries where it will then travel to the lungs. Blood then gets oxygenated in the capillaries of the of the lung which increases the pressure. The blood exits the lungs and proceeds to the pulmonary veins. The blood will enter the left atrium. This is the start of the systemic circulation. First, the oxygenated blood will leave the left atrium via the left atrioventricular valve to reach the left ventricle. The left ventricle has thicker muscle mass due the high pressure needed to pump blood to the rest of the body. The blood flow continues to the aortic valve, which works in a similar way to the pulmonary valve. Next, blood travels to the aorta where is will branch off throughout the bodies into arterioles. There will be a gas exchange causing the blood to be deoxygenated in the capillaries. The Systemic circulations ends when the blood comes back to the heart via the cranial and caudal vena cava. The heart is a complex pump that incorporates many systems to be able to supply blood to your whole body.