Resparation and gas exchange and brething Ghina haniy Respiration Respiration is a chemical reaction which occurs in all living cells, releasing • energy from glucose. 1-Air moves in and out of lungs 2-gas exchange between blood and air at alveoli . 3-co2(carbon dioxide)in blood difuess into air . 4-o2(oxygen)in air diffuess into blood. breathing 1-The intercostal muscles between the ribs contract (get shorter)this pulls the ribs upwards and outwards. 2-Air moves down through the trachea into the lungs to fill an extra air Gas exchange Why we need oxygen All living things need • oxygen to survive Our bodies use it to turn the fuel from our food into energy trachea Nasal cavity pharynx larynx trachea bronchi alveoli