Understanding the respiratory system
The respiratory (breathing) system is made up of the nose and mouth, the pharynx and the larynx, (the space that connects the mouth and nose to the trachea or windpipe), the windpipe (trachea), two tubes that branch from the windpipe into each lung (bronchi), and the lungs.
Each lung is surrounded by a layer of cells supported by connective tissue called the pleurae. This has two layers, the visceral pleura (the layer which covers the lungs, and the parietal pleura (the outer layer which lines the ribcage and the diaphragm). The diaphragm is a sheet of muscle that separates the chest from the upper abdomen.
The lungs are a pair of spongy, air-filled organs located either side in the chest (known as the thorax). We have two lungs (left and right). The purpose of the lungs is to oxygenate blood by bringing in the air we breathe (inhale) and transferring it into the bloodstream so that it can get to every part of the body. These organs also help get rid of gas (waste) by removing carbon dioxide from our bodies each time we breathe out (exhale).