Human Respiratory System

Before I talk about the parts of the respiratory system and some of its function, it will be betterfor us to first understand the reason for breathing.



Why do you need to breathe?
All the cells in your body require oxygen. Without it, they couldn't move, build, reproduce, and turn food into energy. In fact, without oxygen, you will die! So how do you get oxygen? From breathing in air which your blood circulates to all parts of the body.

How do you breathe?
You breathe with the help of your diaphragm and other muscles in your chest and abdomen. These muscles literally change the space and pressure inside your body to accomodate breathing. When your diaphragm pulls down, it not only leaves more space for the lungs to expand but also lowers the internal air pressure.The lower pressure inside the lung allow air to enter more quickly and easily. Outside, where the air pressure is greater, you suck in air in an inhale. The air then expands your lungs like a pair of balloons. When your diaphragm relaxes, the cavity inside your body gets smaller again. The prressure inside the lungs is greater now compared to the pressure outside of the body, so air flows more easily. With the help of your muscles squeeze your rib cage and your lungs begin to collapse as the air is pushed up and out your body in an exhale.

So, it all starts at the nose?
Yup. About 20 times a minute, you breathe in. When you do, you inhale air and pass it through your nasal passages where the air is filtered, heated, moistened and enters the back of the throat. The hairs in your nose trapd foreign particles and prevents them from entering the body. Interestingly enough, it's the esophagus or foodpipe which is located at the back of the throat and the windpipe for air which is located at the front. When we eat, a flap -- the epiglottis -- flops down to cover the windpipe so that food doesn't go down the windpipe.




Parts of the respiratory system
1. The nose hairs helps us to trap the dust particles so does the trachea. The mucus lines the cells of the trachea to trap inhaled foreign or dust particles which the then waft upwards towards the larynx and then the pharynx where it can either be swallowed into the stomach or expelled as phlegm.
2.The bronchus is a passage of airway in the respiratory tract that splits into 2 ways which conducts air into the lungs. No gas exchange takes place in this part of the lungs.
3.An alveolus (plural: alveoli, from Latin alveolus, "little cavity") is an structure that has the form of a hollow cavity. Found in the lung, the alveoli are respiratory sites of gas exchange with the blood. The oxygen rich blood here will be pumped to the heart and circulated round the body.