The pathway of oxygen in the breathing system can be described as follows:
- Oxygen-rich air enters the body through the nose or mouth during inhalation.
- The air then passes through the pharynx (throat) and moves down the larynx and trachea (windpipe).
- From the trachea, air travels into the two main bronchi, which branch into smaller bronchi and then into even smaller tubes called bronchioles.
- The bronchioles lead to tiny air sacs in the lungs called alveoli, where gas exchange occurs.
- Oxygen diffuses across the thin walls of the alveoli into the surrounding capillaries and binds to hemoglobin in red blood cells.
- The oxygen-rich blood is then transported to the heart, which pumps it through arteries to tissues throughout the body.
- In the body’s tissues, oxygen is released from the blood and diffuses into cells to be used in cellular respiration for energy production.
- Carbon dioxide, a waste product, diffuses from the cells into the blood, is carried back to the lungs, and is expelled from the body during exhalation.
This entire process ensures that oxygen is delivered efficiently from the external environment to the body's cells, supporting vital metabolic functions
