The respiratory system encompasses a wide group of organs and tissues that facilitate breathing. The primary function of this system is to supply the blood with oxygen, which is then delivered to various parts of the body.
The main components of the respiratory system are the airways, the lungs and linked blood vessels, and the muscles which pertain to the mechanism of breathing. These all work together for respiration, which is the process of inhalation and exhalation of air.
The function of the airways is to carry air both in and out of the lungs. They are essentially a network of pipes which stretch from the nose and mouth all the way to the lungs.
The air enters first through the mouth or nose, where it is made wet and warm in order to be more suitable for the lungs. It then travels through the voice box and down the wind pipe, which splits up into two bronchial tubes that enter the lungs.
Lungs and Blood Vessels
Once the bronchi reach the lungs, they branch into thousands of smaller, thinner tubes called bronchioles. These eventually end in bunches of tiny round air sacs which are called alveoli.
The alveoli are covered in tiny blood vessels called capillaries, which go on to connect to the network of veins and arteries responsible for the circulation of blood through the body.
The capillaries surrounding the air sacs bring in blood that is lacking in oxygen and rich in carbon dioxide. The carbon dioxide then moves from the blood into the air within the lungs, while at the same time oxygen from the air moves into the capillaries. This oxygen-rich blood then travels to the veins, which carry it to the heart.
The muscles near the lungs are closely associated with the process of breathing. They help the lungs expand and contract, which allows the inflow and outflow of air. These muscles include the diaphragm, intercostal muscles, abdominal muscles, and muscles in the neck and collarbone area.
Among these, the diaphragm is the primary muscle used for breathing. It is shaped like a dome and lies just beneath the lungs, separating the chest cavity from the abdominal cavity. When the diaphragm contracts, oxygen is pulled into the lungs; when it relaxes, carbon dioxide is pumped out.
Beneath the diaphragm are abdominal muscles which facilitate the mechanism of breathing out, usually during the fast breathing which accompanies heavy exercise.
The intercostal muscles also play a vital role in the process of breathing, and are located between the ribs. Other than this, the muscles found in the neck and collarbone area can sometimes assist in breathing when the functionality of other breathing muscles has, in some way, been impaired.