Constructing a lung model is an excellent way to learn about the respiratory system and lung function. The lungs provide a place for gas exchange between air from the outside environment and gases in the blood. The respiratory and cardiovascular systems work together to obtain and circulate gases throughout the body. The heart pumps de-oxygenated blood to the lungs through the pulmonary arteries. Oxygen is picked up in the lungs and the newly oxygenated blood returns to the heart via the pulmonary veins.
Breathing is controlled by a region of the brain called the medulla oblongata. The brain sends signals to muscles in the diaphragm causing them to contract. This contraction causes inhalation and creates low pressure in the chest cavity. As the diaphragm relaxes, pressure within the chest cavity increases resulting in exhalation. In this lung model demonstration, structures of the respiratory system will be represented as follows:
- plastic bottle = chest cavity
- plastic tubing = trachea
- Y-shaped connector = bronchi
- balloons inside bottle = lungs
- balloon covering bottom of bottle = diaphragm