Journey of a Red Blood Cell
The Circulatory System is the main transportation for the body, made up of blood vessels, the blood and the heart. The blood is comprised of the red blood cells, white blood cells (lymphocytes and phagocytes which make up part of the immune system, engulfing invading pathogens), platelets which help the blood to clot preventing infection all transported around the vessels amongst the plasma. The blood plasma contains dissolved substances including carbon dioxide, urea and nutrients. Red blood cells are specialized cells with no nucleus, containing a red colored pigment, haemoglobin which carried oxygen to the respiring cells in the body. They also have a biconcave shape to maximize haemoglobin storage and for flexibility through narrow blood vessels. Once the red blood cell returns to the heart, it enters through the vana cava (vein) returning the deoxygenated blood from the upper part and the lower parts of the body to the heart. This large veins lead into the right atrium where the pumping heart forces the red blood cells through the tricuspid valve into the right ventricle. The valve stops blood from flowing backwards into the right atrium once it’s in the right ventricle they are then pumped through the pulmonary valve into the pulmonary artery and on to the lungs. The arteries carry blood away from the heart (always oxygenated apart from the pulmonary artery which goes from the heart to the lungs), they have thick, elasticated, muscular walls which allows them to expand (creating pulse) and to deal with the high blood pressure. Once the blood is delivered to the lungs via the capillaries (found in the muscles and lungs, microscopic – one cell thick blood vessels which are also very narrow to create very low blood pressure- adapted to maximise diffusion of gases) within the alveoli, an exchange of gases takes place between the gases inside the alveoli and the blood.Blood arriving in the alveoli has a higher carbon dioxide...
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