The lungs

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The lungs are the main part of the respiratory system. This system is divided into the upper respiratory tract and the lower respiratory tract.

The upper respiratory tract includes the:

  • Mouth and nose. Air enters and leaves the lungs through the mouth and nostrils of the nose.
  • Nasal cavity. Air passes from the nose into the nasal cavity, and then the lungs.
  • Throat (pharynx). Air from the mouth is sent to the lungs via the throat.
  • Voice box (larynx). This part of the throat helps air to pass into the lungs and keeps out food and drink.

The lower respiratory tract is made up of the:

  • lungs
  • trachea (windpipe)
  • bronchi
  • bronchioles
  • alveoli

Other parts of the respiratory system help your lungs to expand and contract as you breathe. These include the ribs around the lungs and the dome-shaped diaphragm muscle below them.

The most important function of the lungs is to take oxygen from the environment and transfer it to the bloodstream.

The lungs are the major organs of the respiratory, which helps provide the body with a continuous supply of oxygen. The lungs take more than 6 million breaths per year and affect every aspect of our bodies and health.

Facts on the lungs

  • The left and right lungs are different sizes.
  • The lungs play a part in many functions, including regulating the acidity of the body.
  • Smoking tobacco is the biggest cause of lung-related complaints.
  • Preventive and lifestyle measures can help keep the lungs healthy.

Function of the lungs

The lungs’ main role is to bring in air from the atmosphere and pass oxygen into the bloodstream. From there, it circulates to the rest of the body.

The organs require help from surrounding structures in the body in order to breathe properly. To breath, we use the muscle of the diaphragm, the intercostal muscles between the ribs, the muscles of the abdomen, and sometimes even muscles in the neck.

The diaphragm is a muscle that is domed at the top and sits below the lungs. It powers most of the work necessary in breathing. As it contracts, it moves down, allowing more space in the chest cavity and increasing the lungs’ capacity to expand. As the chest cavity volume increases, the pressure inside goes down, sucking in air through the nose or mouth and down into the lungs.

When air enters the nose or mouth, it travels down the trachea, also known as the windpipe. After this, it reaches a section called the carina. At the carina, the windpipe splits into two, creating two mainstem bronchi. One leads to the left lung and the other to the right.

From there, similar to branches on a tree, the pipe-like bronchi split again into smaller bronchi and then even smaller bronchioles. This ever-decreasing pipework eventually terminates in the alveoli, which are tiny air sacs. Here, gas exchange occurs.