Humans cannot survive without air. Technically it is one of the components of the whole air that is required by the human body. It is called oxygen. Oxygen forms the basis of various cellular pathways that keeps the body running. Blood when mixed with oxygen forms the pure form that is then transported to all parts of the body and from there the oxygen is absorbed by the cells to perform its functions. The respiratory system of human body is really a complex one and is also very interesting. The organs that constitute the complete respiratory system are as follows:
- Nostrils
- Lungs
- Heart
- Blood
The air from outside is inhaled through the nostrils and passed in to the lungs through the wind pipe. The wind pipe consists of the bronchus and other associated bronchial structures. This bronchial structures lead to lungs where the actual gaseous exchange takes place. The lungs are divided into two parts to accommodate complete air exchange. The pair of lungs forms the integral part of the respiratory system. The lungs purify the air and fills with pure oxygen. The oxygen then is taken up by the blood that comes in to the lungs and is routed out to the heart. This form of blood is known as the oxygenated blood or pure blood. The pure blood from the heart is then pumped out to the whole body. At receiving ends the oxygen is taken up and the blood is returned backed to the heart to be transported back to the lungs for purification. The cycle continues till the end of the life.
The gaseous exchange and oxygen is very much required for various biochemical pathways. One of the most important pathways of producing ATP, oxygen plays a crucial role. Oxygen in fact helps complete the cycle. ATP is energy packets or fuel molecules that actually run the body.
Since lungs are completely open to the environment, thus it is exposed to a lot of infectious agents from outside. Thus the airway epithelium is lined by the WBC’s. WBC’s help protect the body from various infections at the entry point. With air comes in lot of allergens and stuff that cause a number of secondary infections in the body. These infections are prevented by the protective epithelium layer in the lungs.
Damage to lungs can be deadly and cause death. Smoking is a major factor of lung damage and hence humans should refrain from this activity.