Four		Pulmonary veins empty into this
Aortic Valve		Nature of blood as it returns to the heart from the lungs
Inferior Vena Cava		Separates the left ventricle from the aorta
Capillaries		Vessel by which deoxygenated blood leaves the heart
Four		Waste product of metabolism
Carbon Dioxide		Smallest arteries in the body
Aorta		Separates the right ventricle from the pulmonary artery
Left Ventricle		Get larger as they approach the heart
Right Ventricle		Empties into the lower portion of the right atrium
Arterioles		Smallest veins in the body
Veins		Organs that take in oxygen and give off carbon dioxide
Right Atrium		Route by which oxygenated blood returns to the heart
Tricuspid Valve		First chamber of the heart
Arteries		Has two leaves or flaps
Arterioles		Room air is 21% this
Pulmonary Artery		Powerhouse of the heart...strongest of all chambers
Oxygen		Capillaries drain into these small vessels
Left Atrium		Tricuspid valve opens into this
Superior Vena Cava		Place at which gas exchange occurs
Pulmonary Valve		Vessels that empty into the capillary bed
Venules		Nature of blood as it returns to the heart from the body
Pulmonary Vein		Number of chambers in the heart
Deoxygenated		Number of valves in the heart
Venules		Get smaller as they get farther away from the heart
Lungs		Empties into the top portion of the right atrium
Oxygenated		Separates the right atrium from the right ventricle
Bicuspid Valve		Largest artery in the body