The respiratory system functions as a gas exchange that help us breathe. It is made up of organs in the body that delivers oxygen and takes away carbon dioxide. We cannot survive without oxygen and we cannot live if our breathing stops. This makes the respiratory system the essential part of human body and other living creatures.



The respiratory system is responsible for gaseous exchanges that help us breathe. It is situated in the thorax between the alveoli and the capillaries. The anatomy of exchanging oxygen and carbon dioxide vary depending on the organism.

The respiratory system involves different functions in the body that generally aids in the entire respiration process in order for us to breathe easily. First is the ventilation process in which clean air is inhaled and old air is exhaled. Lungs are ventilated by the muscles of respiration.

The autonomic nervous system controls ventilation. There is an area in the brain that forms a respiration regulatory center (interconnected brain cells) which manages respiratory movements.

Inhalation is the movement of air from the external environment through the air ways and into the alveoli. It begins by the contraction of the diaphragm, the main driver of inhalation in normal conditions. It is sustained by external intercostal muscles. However, the muscles of respiration aid in the expansion and support, particularly during respiratory failure. Lastly, the air is filtered and warmed and then it flows to the lungs.

Air is exhaled out during this process. It is done by the abdominal and internal intercostal muscles. Air flows out until the pressure reaches its balance in the chest and the atmosphere.

Circulation is the process that moves substances to and from the cells. It begins with the pumping of blood from the right ventricle (one of the four chambers in the heart) to the pulmonary valve (maintains unidirectional flow of blood in the heart) and into the pulmonary arteries (carry blood from heart to the lungs). The vessels go with the airways and undergo several branching. Blood goes back into the heart once the gas exchange is complete.

Gas exchange is the main function of the respiratory system. It evolves between the external environment and the circulatory system of an organism. Gas exchange occurs at the alveoli (tiny sacs). The oxygen molecules and the carbon dioxide exchanged by diffusion (transport of molecules from one region of higher concentration to one of lower concentration in a random molecular motion).

Division and Parts

Respiration is the process of breathing in and out of the entire functioning system. It is subdivided based on the anatomical features of a certain organism. There is the upper respiratory tract and lower respiratory tract. Upper respiratory tract includes the nasal passages, the larynx and the pharynx. The lower part consists of the trachea, bronchi and the lungs. It can also be divided into functional or physiological zones. Thus, the conducting zone transports gas from the outside atmosphere. The transitional and respiratory zones functions at the alveolar region where gas exchange occurs.

Air intake initially takes place in the nasal passages through the pharynx (canal leading to esophagus) and the larynx (an organ in the neck that involved in protection of the trachea and sound production). It will then pass through the lower airways like the trachea or windpipe. It filters the air as we breathe and goes to the bronchi. The two air tubes in the bronchi branches off and conducts air into the lungs.

The main part of the respiratory system is the lungs located in your chest. It is protected by your rib cage that connects to the spine. These bones go around the lungs to protect it. The two lungs are responsible in taking in oxygen and breathing out carbon dioxide. The red blood cells deliver oxygen into the entire body and picking up waste gas produced by body cells. The diaphragm helps the lungs to inhale and exhale. It is a domed-shaped muscle that contracts and flattens to allow the ribcage to move up and out.

Other animals and plants have simple and different anatomical features. It is very essential to life. We breathe everyday without thinking about it. It is better to always keep our entire respiratory system healthy to work properly.