Heart

Is a sac filled with serous fluid. It is made of fibrous tissue that have has two layers. The deepest layer is called the visceral pericardium and the most superficial is called the parietal pericardium. The pericardium serves to limit the friction as the heart is beating   

Is where the caudal and cranial vena cava enter the heart. The deoxygenated blood enters the right atrium 

The pulmonary vein enters the heart here. The oxygenated blood enters the left atrium from the lungs 

The deoxygenated blood enters the right ventricle from the right atrium through the Tricuspid Valve. this blood is then pumped out through the pulmonary valve to the pulmonary artery to the lungs.

Oxygenated blood enters into this chamber from the left atrium through the Bicuspid Valve. The blood from this chamber then is pumped through the aortic valve to the aorta 

The bottom pointed area of the heart that always points left 

The wall of the heart that separates the left ventricle from the right ventricle 

These muscles are located in the ventricles. They control the opening and closing of the valves between the ventricles and the atriums 

These fibers are are connected from the papillary muscles to the valves. These fibers pull the walls of the valves causing them to open and close 

Located between the right atrium and right ventricle, separating them. It allows the blood to flow from the atrium to the ventricle 

Located between the left atrium and the left ventricle, separating them. It allows the blood to flow from the atrium to the ventricle 

Are a type of valve in the heart that have three folds. These valves include the pulmonary valve and the aortic valve.