(3)	Respiratory+system+structure

Each day we breathe about 20,000 times. All of this breathing couldn’t happen without help from the respiratory system. The human respiratory system is very important. This is because it transports air into the lungs and it facilitate the diffusion of oxygen into the human blood stream. The respiratory system also allows the person to receive waste carbon dioxide from the blood and exhales it.

The human respiratory system is mainly composed of nasal passage, pharynx, larynx, trachea, bronchus, and lungs. It is responsible for the process of respiration which is crucial for living beings. Respiration is the process of obtaining and using oxygen, while eliminating carbon dioxide. It is the process by which human take in the oxygen from the air and give out the product of chemical reactions within the cells, the carbon dioxide. The specialized system that brings about this process of respiration is known as the human respiratory system. Lets take a look at the structure of this important system of the human body ("Lungs and Respiratory System").

The respiratory system can be divided into the upper respiratory tract which can be found in head and neck and it consists of the nasal passages, pharynx and the larynx AND the lower respiratory tract which are located in the chest and includes the trachea, the primary bronchi and the lungs (" Major Zones and Divisions"). ..

Now lets take a look at how each structure contributes to the Respiratory System...



The **NASAL CAVITY** is an entrance for outside air to enter the body. The nose has hairs inside it that are used as a filter.
 * Upper Respiratory Tract: **

The **ORAL CAVITY** is also another entrance for air to go through. Air usually enters through the mouth when the nasal cavity is blocked, maybe by a cold or something.

NX is a tube where air is carried from the entrance to the entrance of the trachea
 * PHARY**


 * EPIGLOTTIS** is like a gate, that opens when air is passing through down to the lungs, and closes when anything is being swallowed, where it should go down to the stomach.


 * LARYNX**, also known as the voice box, is where the vocal chords are, it is where moving air goes in and out of to make noise (your voice).


 * Lower Respiratory Tract: **
 * TRACHEA** is the tube that carries air from the exit of the **PHARYNX** into the lungs.


 * BRONCHUS** is where the **TRACHEA** splits into two, to make air go into the right and left lungs.


 * RIGHT LUNG** is divided into three or sections.


 * LEFT LUNG** is divided into two sections.


 * PLEURA** are two membranes, or walls, separating the lungs from the chest walls.


 * DIAPHRAGM** is the wall between the abdominal cavity and chest cavity. When moving downwards, it makes the lungs suck in air, making the nasal/oral cavity take air into the lungs, expanding them.


 * ALVEOLI** are where the air that is breathed in goes. They are shaped like small bags.


 * CAPILLARIES** are blood vessels, that are against the walls of the alveoli. They are in charge of taking oxygen from the air into the blood.


 * MUCUS** is a liquid that is carried upwards, through the throat and out the nasal or oral cavity, or it is swallowed. Mucus is in charge of gathering the dust upward and out into the throat, where it is either coughed up or swallowed.

media type="youtube" key="HiT621PrrO0" height="370" width="498"
 * Respiration-Ventilation 3D Medical Animation:**

Works Cited “Major Zones and Divisions.” Get Body Smart. N.p., n.d. Web. 9 June 2012. . Oak, Manali. “Structure of the Human Respiratory System.” Buzzle.com. 2012 Buzzle.com, n.d. Web. 9 June 2012. . “Lungs and Respiratory System .” //Kidshealth //. N.p., n.d. Web. 4 June 2012. .