How does oxygen get in the respiratory system
Oxygen enters the respiratory system through a process called respiration. Respiration refers to the exchange of gases between the external environment and the body's tissues.
The first step in the process is inhalation, where air is taken in through the nose or mouth. The air then travels through the nasal cavity or mouth, down the trachea or windpipe, and into the lungs.
Once inside the lungs, the air passes through the bronchi, which are branched airways that get smaller and smaller, eventually leading to microscopic air sacs called alveoli. It is within these alveoli that the exchange of gases between the lungs and bloodstream occurs.
The walls of the alveoli are thin and lined with a network of tiny blood vessels called capillaries. Oxygen from the air diffuses across the walls of the alveoli and into the capillaries, where it binds to hemoglobin, a protein in red blood cells that transports oxygen throughout the body.
At the same time, carbon dioxide, a waste product of cellular metabolism, is released from the body's cells into the bloodstream. Carbon dioxide then diffuses out of the capillaries and into the alveoli.
During exhalation, the carbon dioxide-containing air is expelled from the lungs through the bronchi, trachea, and ultimately through the nose or mouth.
Therefore, oxygen enters the respiratory system through inhalation and is transported to body tissues by the circulatory system, while carbon dioxide is exhaled from the body's tissues and expelled through exhalation.