lungs and heart

• the air that goes through the trachea , then splits into two tubes called bronchi
• the bronchi then further split into bronchioles
• bronchioles have small bags called aveoli where gas exchange happens
• oxygen diffuses out of alveoli's and into blood
• carbon dioxide diffuses out of the blood into the aveous capillaries and into the alveoli
• blood leaves the lungs and travels around the body
• what are the four chambers

  right atrium, right ventricle, left atrium, left ventricle
• the ventricles contract forcing the blood into the...

  pulmonary artery and aorta, and out of the heart
• the blood flows to the organs by arteries and returns to the heart by veins