Human circulatory system

• Mammals have a double circulatory system
• Blood in the right side of the heart is deoxygenated and the blood in the left side of the heart is oxygenated
• The heart is always shown as if you're facing a person so the right side is shown on the left and the left side is shown on the right
• Arteries


  Blood leaves the heart in arteries, blood in arteries is under very high pressure and the pressure increases every time the heart contracts, this is called the pulse, blood continually moves forward in arteries even between contractions
• Pulmonary artery


  Carries deoxygenated blood from the heart to the lungs
• Aorta


  Very large artery that carries oxygenated blood from the heart to the body
• Renal arteries


  Arteries that supply the kidneys
• Arterioles


  Blood vessels that blood passes through before reaching the organs
• Capillaries


  Very narrow blood vessels where gas exchange occurs, low blood pressure and the blood is no longer surging in pulses
• Venules


  Blood vessels that blood passes into after leaving the capillaries
• Veins


  Carry oxygenated blood away from the organs towards the heart, blood is under relatively low pressure and not surging in pulses
• Renal veins


  Veins that come from the kidneys
• Vena cava


  Very large vein that returns the deoxygenated blood back to the heart
• Pulmonary vein


  Carries oxygenated blood from the lungs to the heart
• The structure of the different blood vessels depends on the function of each blood vessel