human transport system Flashcards
describe white blood cell
also known as leucocytes. produces antibodies to prevent pathogens or viruses from invading the body.
phagocytes are irregular in shape so it can move, change shape and squeeze through capillaries. it engulfs foreign particles such as bacteria by phagocytosis.
lymphocytes produce antibodies when pathogens and disease causing bacteria enters the bloodstream. protects the body by agglutination which causes bacteria to clump together to attract phagocytes to engulf the clumped bacteria by phagocytosis. it also helps to neutralise toxins produced by bacteria
describe red blood cell
it is also known as erythrocytes and transports carbon dioxide and oxygen. life span of 120 days and is destroyed in the spleen and liver.
biconcave shape increases surface area to increase rate of diffusion of oxygen and carbon dioxide
presence of haemoglobin to combine reversibly with oxygen to form oxyhaemoglobin enabling blood to transport oxygen from lungs to all part of the body
absence of nucleus allows more haemoglobin to be packed
elastic bell shape allows it to squeeze through blood vessels smaller than itself without breaking
describe blood plates
it is also known as thrombocytes functioning to prevent excessive blood loss and entry of pathogens by forming platelet plug/ blood clotting
describe mechanism of blood clotting
when blood vessels are damaged, damaged tissues and platelets produces thrombokinase which converts prothrombin into thrombin. thrombin convert insoluble fibrinogen into soluble fibrin threads that trap blood cells and forms a clot/ scab
describe the transfer of materials between capilaries and tissue fluid
tissues and cells are surrounded by tissue fluid which fills intercelluar spaces and acts as a medium for materials to diffuse between blood and cells of the body.
materials are exchanged between capillaries and tissue fluid by diffusion. oxygen glucose, amino acids, mineral salts present in the tissue fluid diffuse from the blood via the tissue fluid into cells. metabolic waste diffuse from cells via tissue fluid to the blood
