Circulation/respiration: Co2 molecule from brain to atmosphere
Co2 molecule travels from brain to heart through veins
Co2 Molecule enters inferior vena cava, right atrium, tricuspid valve, right ventricle, pulmonary valve, pulmonary artery, and into the lungs again through capillaries
Gas exchange occurs, o2 switches with co2
co2 travels up bronchioles, secondary and primary bronchi
Molecule travels up trachea and esophagus upon exhalation
co2 molecules travels out mouth/nose and is released into the atmosphere.
