The respiratory system is situated in the thorax, and is responsible for gaseous exchange between the circulatory system and the outside world. Air is taken in via the upper airways (the nasal cavity, pharynx and larynx) through the lower airways (trachea, primary bronchi and bronchial tree) and into the small bronchioles and alveoli within the lung tissue. Move the pointer over the coloured regions of the diagram; the names will appear at the bottom of the screen)  The lungs are divided into lobes; The left lung is composed of the upper lobe, the lower lobe and the lingula (a small remnant next to the apex of the heart), the right lung is composed of the upper, the middle and the lower lobes


Airways

The airways are pipes that carry oxygen-rich air to your lungs. They also carry carbon dioxide, a waste gas, out of your lungs. The airways include your:

  • Nose and linked air passages (called nasal cavities)
  • Mouth
  • Larynx (LAR-ingks), or voice box
  • Trachea (TRA-ke-ah), or windpipe
  • Tubes called bronchial tubes or bronchi, and their branches


What are the functions of the lungs?
  The lungs take in oxygen, which the body's cells need to live and carry out their normal functions. The lungs also get rid of carbon dioxide, a waste product of the cells.  The lungs are a pair of cone-shaped organs made up of spongy, pinkish-gray tissue. They take up most of the space in the chest, or the thorax (the part of the body between the base of the neck and diaphragm).  The lungs are enveloped in a membrane called the pleura.  The lungs are separated from each other by the mediastinum, an area that contains the following

  • Heart and its large vessels
  • Tachea (windpipe)
  • Esophagus
  • Thymus
  • Lymph nodes