The nose is the upper most structure of the respiratory system and can be thought of as the portal to the lungs. Air can enter the body only through the nose or the mouth. In a healthy person, the majority of air enters through the nose (except in times of exertion or distress). Newborn babies breathe exclusively through the nose. If their nose is partially obstructed, they will not be able to feed well and will have difficulty breathing. If the nose of a newborn is totally obstructed he or she won’t be able to breathe at all. A newborn’s voice box essentially protrudes into the nasopharynx, cutting off the mouth from the airway. A newborn with a total obstruction of the nose will have a bluish skin tone and will need the instillation of a special breathing tube.
As children get older, they are able to breathe through their mouth more readily because their voice box drops as they grow, permitting the air that enters their mouth to flow into the lungs (2). Adults automatically breathe through their nose with a closed mouth, unless
they experience nasal blockage, which forces them to breathe through an open mouth. Most people have partial obstruction of their nose and breathe through their nose and their mouth. This is not normal, even though many of us think that it is, because we are designed to breathe through our nose only.
Once air has been taken in through the nose, it passes along the same path as the mucus: it first moves into the sinuses and gets filtered. It then comes out of the sinuses and enters the nasopharynx and the throat. At this point, air and mucus take different paths. The mucus passes behind the larynx into the esophagus, while the air passes through the larynx and into the trachea (the windpipe), the bronchi, and lungs. Once air reaches the lung tissue, the air passes into the bronchioles, which are small branches, and then the alveoli, which are the terminal ends of the airway. It is in the alveoli that oxygen passes through the membranes of the lung into the venous bloodstream (3).
In the bloodstream, oxygen links up with red blood cells that travel through pulmonary veins and blood vessels toward the heart. The heart
then distributes the oxygen-rich blood to your organs, muscles, brain, other parts of the body via the arteries. Your body’s tissues replace the oxygen (O,) with carbon dioxide (CO,). After the arterial blood releases the oxygen, the veins take the deoxygenated blood (which is low in oxygen and high in CO,) back to the heart, which sends it to lungs to pick up more oxygen.
If the nose doesn’t work properly, the air taken into the lungs will not be filtered, humidified, and heated. This decreases the exchange of oxygen with carbon dioxide in the bloodstream, and cells throughout the body will not get the proper amount of oxygen delivered to them.