Blood enters the atria aorta ventricles pulmonary artery( atria, aorta, ventricles, pulmonary artery ) of the heart. The aorta pulmonary artery ventricles atria( aorta, pulmonary artery, ventricles, atria ) contract expand( contract, expand ) and force blood into the ventricles atria vena cava aorta( ventricles, atria, vena cava, aorta ). The vena cava aorta atria ventricles( vena cava, aorta, atria, ventricles ) contract expand( contract, expand ) and force blood out of the heart. Valves Veins Arteries Capillaries Tissues( Valves, Veins, Arteries, Capillaries, Tissues ) in the heart ensure that blood flows in the correct direction as quickly as possible in small increments( in the correct direction, as quickly as possible, in small increments ). Blood flows from the heart to the organs through arteries veins capillaries( arteries, veins, capillaries ) and returns through veins capillaries arteries( veins, capillaries, arteries ).
There are two separate circulatory digestive respiratory( circulatory, digestive, respiratory ) systems - one for the lungs heart kidneys muscles( lungs, heart, kidneys, muscles ), and one for all the other organs in the body.

Coronary heart disease Strokes Myocardial infarctions Cardiac arrests( Coronary heart disease, Strokes, Myocardial infarctions, Cardiac arrests ) can be caused by fatty deposits cholestrol deposits lipid deposits amino acid deposits( fatty deposits, cholestrol deposits, lipid deposits, amino acid deposits ) building up on the inner surface of arteries veins capillaries( arteries, veins, capillaries ). These deposits restrict blood flow and can cause heart attacks strokes paralysis heart failure hypertension( heart attacks, strokes, paralysis, heart failure, hypertension ). Stents Enzymes Stem cells( Stents, Enzymes, Stem cells ) can be inserted into the arteries veins capillaries( arteries, veins, capillaries ) and can increase the blood flow to the heart muscles lungs tissues respiratory system( heart muscles, lungs, tissues, respiratory system ).
Stents do have some drawbacks: they can irritate the artery lining vein lining bloodstream( artery lining, vein lining, bloodstream ), causing scar tissue excess muscle tissue bacteria( scar tissue, excess muscle tissue, bacteria ) to grow there, and drugs must be taken to avoid blood clotting build-up of proteins excess cholestrol deoxygenation of blood( blood clotting, build-up of proteins, excess cholestrol, deoxygenation of blood ) in the stent itself.

TRANSPIRATION SYSTEM - The movement diffusion( movement, diffusion ) of water from the roots leaves waxy cuticle( roots, leaves, waxy cuticle ) through the xylem phloem stem roots( xylem, phloem, stem, roots ) and out of the leaves roots stem( leaves, roots, stem ) is called the transpiration system.