circulatory system

• circulatory system is a continues network of tube running through the body that interact with all 11 systems
• functions of circulatory system: carry oxygen and nutrients to all body cells, also bring carbon dioxide and waste away from them
• deoxidised blood enters the inferior vena cava, to the right atrium, to the right ventricle, to the pulmonary artery and to the lungs for gas exchange
• oxidised blood from the lungs comes back to the heart from the pulmonary vein, to left atrium, left ventricle, and to the aorta to other parts of the body
• the heart has 4 muscular chambers, separated by one -way valves to prevent blood from moving backwards
• right side of heart receives deoxygenated blood from bogy and sends to lungs for gas exchange
• left side of heart receives oxygenated blood from lungs and send it out to rest of body through aorta
• arteries are made of thick muscle layers and elastic connective tissue, supporting the flow of high-pressured blood away from the heart
• the structures of arteries makes the contracts to prevent vessels from exploding due to the high pressure from the heart
• veins are made out of thin muscle layers and elastic connective tissue, supporting the flow of low pressure blood back to the heart.
• Since the pressure in veins is low on the return trip, therefore veins have a series of one way valves to compensate
• capillaries are only 1 cell thick, it is so narrow that blood cells are squeezed through to ensure maximum gas exchange
• Red blood cells delivers oxygen and removes waste from all body cells
• red blood cells get their colour from interaction between oxygen they carry and protein
• white blood cells produce protective antibodies, surround and destroy bacteria as part of immune system
• plasma transport mechanism for microbe-fighting antibodies, cellular waste and hormones
• platelets stick surface that let them form fibrous clots to stop any bleeding