After blood passes through the body, giving oxygen to where it's needed, it returns to the heart. In the heart, the blood is cleansed thoroughly. CO2 is removed and oxygen is put into the blood, oxygen coming from your windpipe when you breathe.
So to simply answer your question: CO2
blood takes oxygen and gives carbon dioxide to the lungs
The answe to this question at a primary school level is that the lungs absorb carbon dioxide CO2 from the blood and then feeds oxygen O2 back into the bloody stream
Gas exchange happens in the bed of CAPILLARIES in the lungs.
oxigen is the gas that enters the blood through the lungs
oxigen is the gas that enters the blood through the lungs
Oxygen is the gas that enters the blood during inspiration. It is taken into the lungs from the outside air and then diffuses into the blood vessels in the lungs.
Oxygen
oxygen
Oxygen.
carbon dioxide
carbon dioxide
The pulmonary artery is the main artery that carries blood to your lungs.