Respiratory System Functions

Respiration is defined as the process of inhalation of oxygen and the exhalation of carbon-di-oxide with the help of certain organs of the human body. These organs include the nose, pharynx, larynx, trachea, bronchi and the lungs. These organs together make the human respiratory system. Let us get to know more about the organs of respiratory systems.

The Human Respiratory System
The human 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.
• Pharynx - It is situated behind the mouth and is the passage to the stomach and the lungs.
• Larynx - It is present at the top of trachea and contains vocal cords. It is also known as the voice box.
• Trachea (windpipe) - It is a tube like structure that helps in passage of air from larynx to the bronchi.

The Lower Respiratory Tract:

• Bronchi (bronchioles) - These are the branches of the bronchi that conduct air into the lungs.
• Alveoli (air sacs) - The sacs in the lungs where gas exchange occurs.
• Lungs - The two inverted-cone shaped organs present in the chest of human beings

Read more on:

• Organs of the Respiratory System
• Structure of the Human Respiratory System

Human Respiratory System Functions
The following are the different functions of the respiratory system.

Respiration
The most important function of the respiratory system is the process of respiration. How does the respiratory system function? Let us have a look at it in detail.

Inhalation
When a person breathes air (which contains oxygen), it passes through the nasal passages containing mucous. This mucous helps in filtering out contaminants like dust, pollen and smoke. The nasal epithelium naturally adds moisture and heat to the air. The larynx prevents food or liquid entering the respiratory tract. The air then passes through the larynx and enters the trachea or the windpipe. Here it gets divided into the two bronchi that connect the trachea to the lungs. The bronchi again gets split into many smaller tubes known as bronchioles. These bronchi end in air sacs, also known as alveoli, which contain blood capillaries. These blood capillaries carry blood which comes through veins from all other parts of the body. Here the carbon-di-oxide from the blood is exchanged for the oxygen in the alveoli. The blood containing oxygen then goes to the heart where it is later pumped to other parts of the body.

Exhalation
Exhalation in human beings is the process of expelling out of air containing carbon-d-oxide. The movement of the air while exhalation is through the bronchi, then through the airways and then it passes out through the nose. The exhaled air is completely depleted of oxygen.

The lungs are the most important organs of the human respiratory system. There is a muscle located below the lungs known as the diaphragm which 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 which helps in forcing the air out of the lungs.

Vocalization
Vocalization is also one of the major respiratory system functions. Vocalization is the process which enables humans to speak and also to make sound. When the air passes through the pharynx and larynx, it makes the vocal cords in larynx to vibrate which helps in production of sound and speech in humans.

Coughing
When any foreign particles enter the nasal passages, it can result into irritation. Therefore, expelling out these foreign bodies or irritants is one of the functions of the respiratory system. These irritants are forced out of the respiratory tract through cough or even sneeze.

Read more on respiratory system facts.

The respiratory system functions are very important for our body, and hence the respiratory system is considered as one of the five major human body systems.