4.3 Explain how the respiratory system (nose, pharynx, larynx, trachea, lungs, alveoli) provides exchange of oxygen and carbon dioxide.
Vocabulary
lungs - organs responsible for bringing in oxygen and exhaling CO2
bronchial tubes - air pathways in the lungs
alveoli - microscopic regions in the lungs where gas is exchanged
Respiratory System
The respiratory system allows for gas exchange. Carbon dioxide out and oxygen in. This is done through the windpipes including the bronchial tubes in the lungs.
PATH OF AIR
Air first enters the nose (or mouth) and is filtered by the sinuses in the nasal cavity. Then it travels down the through the pharynx (throat) and larynx (voice box) into the trachea (windpipe). It then moves into the lungs bronchial tubes which get smaller and smaller until it reaches the end in the ALVEOLI. In the ALVEOLI, oxygen is added to the blood and carbon dioxide is removed. The air then travels the opposite direction, out of the body.
Alveoli
In the alveoli, microscopic areas in the lungs, gases are exchanged in the blood. Notice the blue and red blood vessels. The blue ones lack oxygen and the red ones have oxygen!