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Respiratory System


The major job of the respiratory system is gas exchange between the external environment and a person's circulatory system. This exchange allows the blood to receive oxygen and the removal carbon dioxide and other gaseous wastes from the circulation.


Parts of the respiratory system


The two major organs of the respiratory system where oxygen is taken in and carbon dioxide is breathed out. The left lung is divided into two lobes and the right lung is divided into three lobes.


Small air sacs in the lungs where many capillaries exchange carbon dioxide for oxygen to be taken to the body.


The sinuses are small spaces in the skull and are thought to regulate the temperature and humidity of the air breathed in.


The more common passage that air enters into the body. It has hairs that clean the air as it enters the nose.


The mouth is the secondary passage for air into the body and is a back up for when the nose is clogged and can't bring in the air to the body.

Adenoids and tonsils

These are lymph tissue and lymph nodes that help protect the body from infection.


This is a passageway that carries air down to the trachea or windpipe.


Also called the windpipe, it connects the larynx to the lungs.


This is a flap over the trachea that keeps out food or anything that could clog the trachea.


This is the voice box. When air passes through it, sound can be made.

Bronchi and bronchial tubes:

These carry air into the lungs.


A large muscle that separates the chest cavity from the abdominal cavity. When it presses downward, it allows air to enter the lungs.


Heart and Lungs Diagram


Heart and Lungs




Respiratory System Videos

Respiratory System Quiz



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