Matching Pairs How our four systems workOnline version Match each system with its function. by África Pedrosa Salvador 1 Respiratory system 2 Excretory system 3 Circulatory system 4 Digestive system It transforms the food we eat into nutrients and passes them to the blood. It also expels the undigested food out of the body as faeces. It passes the oxygen it takes from the air to the blood. It also released carbon dioxide out of our body. It consists of the urinary system and the sweat glands. It eliminates the waste substances produces by the cells and mixes them with water to produce urine and sweat. It carries the nutrients and the oxygen to your cells. It also transports waste substances.