Blood and the heart

• Blood transports oxygen and nutrients to our cells and removes waste products
• Blood is a tissue
• Plasma transports substances around the body
• Red blood cells transport oxygen
• The function of platelets is to clot blood
• Blood clotting prevents blood loss and prevent the entry of micro organisms
• White blood cells fight against infection
• Arteries carry blood away from the heart
• Veins carry blood towards the heart
• Capillaries connect arteries and veins
• The circulatory system consists of arteries, veins, capillaries and the heart
• Arteries have thick walls, no valves and narrow lumen
• Veins have a thin wall, have valves and wide lumen
• The four chambers of the heart are; left atrium, left ventricle, right atrium and right ventricle
• Ventricles are at the bottom of heart
• The left ventricle has thicker walls, as blood is pumped from here to all over the body
• The right ventricle pumps blood from here to just the lungs
• Cardiac muscle never tires
• Major blood vessels are vena cava and pulmonary artery (right side), aorta and pulmonary vein (left side)
• Pulmonary artery carries deoxygenated blood to lungs, pulmonary vein carries oxygenated blood to left atrium