The respiratory system and breathing rate
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Explainer Video
Summary
The respiratory system and breathing rate
In a nutshell
The lungs are one of the main organs of the respiratory system. The alveoli are the site of gas exchange within the lungs. An individual's average breathing rate can be calculated using a simple equation.
The respiratory system
The lungs (6) are found in the thorax, which is the top part of the body. The thorax is separated from the lower part of the body by an organ called the diaphragm (8). There are two lungs in the thorax which are surrounded by the pleural membranes and protected by the rib cage.
When a person breathes in, the air flows from the mouth (1), through the trachea (4) and into the two bronchi (5). The bronchi go into each lung, where they split into smaller bronchioles (7). The bronchioles end at the alveoli (9) which are small air sacs. Gas exchange occurs at the alveoli.
Alveoli
The alveoli are small air sacs surrounded by a network of blood capillaries and are the site of gas exchange in the lungs. The lungs contain hundreds of millions of alveoli.
Blood from the body passes alongside the alveoli in the capillaries, containing little oxygen and lots of carbon dioxide. The carbon dioxide diffuses from the blood out into the alveolus to be breathed out. Oxygen diffuses from the alveoli into the blood to be transported to the body’s cells. When near the body’s cells, the red blood cells release oxygen for use in respiration.
Breathing rate
A person’s breathing rate can be calculated using a simple equation.
Example
Henry takes in . Calculate his average breathing rate in .
FAQs - Frequently Asked Questions
What path does air take to enter the lungs?
When a person breathes in, the air flows through the trachea and into the two bronchi. The bronchi go into each lung, where they split into smaller bronchioles. The bronchioles end at the alveoli which are small air sacs. Gas exchange occurs at the alveoli.
What are the alveoli?
The alveoli are small air sacs surrounded by a network of blood capillaries and are the site of gas exchange in the lungs. The lungs contain hundreds of millions of alveoli.
Where are the lungs found in the body?
The lungs are found in the thorax, which is the top part of the body.