Respiration is defined as the process of inhalation of oxygen in the body and exhalation of carbon dioxide out of the body. This is carried out with the help of organs of the respiratory system, i.e. nose, pharynx, larynx, trachea, bronchi, lungs, and respiratory muscles. Let us know more on it.
The Human Respiratory System
The respiratory system is divided into two parts, viz., the upper respiratory tract and the lower respiratory tract. The following are the organs of the upper and the lower respiratory tract.
The Upper Respiratory Tract
- Nose (nostrils) - It is the entrance of the respiratory tract and helps in allowing air to flow in and out. It humidifies, warms, and filters the air that comes in.
- Pharynx (throat) - It is located at the back of the mouth, and connects the mouth to the esophagus (food pipe). It is a passage for air and food.
- Larynx - It is present at the top of trachea and contains vocal cords. It is also known as the voice box. It helps in controlling breathing and swallowing.
- Trachea (windpipe) - It is a tubelike structure that helps in passing air from larynx to bronchi. It also warms the air and prevents foreign bodies from entering lungs.
The Lower Respiratory Tract
- Bronchi - These are the airways of the lungs diverging from the trachea. They carry air in and out of the lungs.
- Bronchioles - These are branches of the bronchi that conduct air into the lungs. They perform the same function as the bronchi.
- Alveoli (air sacs) - These are sacs in the lungs and contain elastic fibers. The exchange of carbon dioxide and oxygen occurs here.
- Lungs - These are the two inverted-cone shaped organs present in the chest of human beings. The function of lungs is to take in oxygen into the body and expel carbon dioxide.
Functions of the Human Respiratory System
As mentioned above, respiration or breathing, is the function of the respiratory system. Lungs are the vital organs of the respiratory system. There is a muscle located below the lungs known as the diaphragm. It also plays an important role in the process of respiration. During inhalation, the diaphragm contracts, creating a vacuum that helps in pulling air into the lungs. On the other hand, during exhalation, the diaphragm relaxes and helps in forcing the air out of the lungs.
When a person breathes air (comprising oxygen), it passes through the nasal passages containing mucus. The mucus helps in filtering out contaminants like dust, pollen, and smoke. The nasal epithelium adds moisture and heat to the air. The air then passes through the larynx and enters the trachea or the windpipe.
Here, it gets divided into two bronchi that connect the trachea to lungs. The bronchi further split into many smaller tubes known as bronchioles. They end in air sacs, also known as alveoli, that contain blood capillaries. These blood capillaries carry blood that comes through veins from all other parts of the body. Here, the carbon dioxide from the blood is exchanged for the oxygen in alveoli. The blood containing oxygen then goes to the heart where it is later pumped to other parts of the body.
Exhalation is the process of expelling out of air containing carbon dioxide. The movement of the air, while exhalation, is through the bronchi, then through the airways, and lastly, it passes out through the nose. Inhalation and exhalation, together, complete the process of respiration.
Apart from respiration, the respiratory system also helps in performing other functions like vocalization and cough production. Vocalization is the process that enables humans to speak and to make sound. When the air passes through the pharynx and larynx, it makes the vocal cords in the larynx to vibrate. The vibration helps in production of sound and speech in humans.
The nasal passage tends to get irritated if any foreign particle enters it. Therefore, expelling out these foreign bodies or irritants is essential. These irritants are forced out of the respiratory tract through cough or sneeze.
Prolong exposure to air pollution or other pollutants like asbestos, harmful chemicals, dust, cigarette smoke, tobacco smoke, allergies, infection, genetics, etc., lead to diseases of the respiratory system. Asthma, bronchitis, pneumonia, COPD, emphysema, tuberculosis, lung cancer, etc., are some of the diseases and illnesses of the respiratory system.
The respiratory system is considered as one of the five major human body systems. Keeping yourself free from smoking, or preventing exposure to air pollutants will help in preventing diseases related to the respiratory system to a great extent. Take care!
Disclaimer: This article is for informative purposes only, and should not be used as a replacement for expert medical advice.