Our respiratory system is made up of a group of organs that obtain the oxygen we need to live.

Most of them are protected inside the ribs, spinal column and breastbone.

To move this ribscage we use a muscle: the diaphragm.

    All of them coordinate theirs tasks and movements.

       Nose (nostrils), mouth , pharynx and larynx.

The movement of gas through the larynx, pharynx and mouth allows humans to speak, or phonate

Air enters into the nose and goes to the lungs.

       Trachea, bronchi and lungs (alveoli).

    Left lung is smaller than the right one, because it has to give place to the heart.

Ventilation occurs under the control of the autonomic nervous system .

 This area of the brain forms the respiration regulatory center, a series of interconnected brain cells which coordinate respiratory movements

Inhalation

When the diaphragm contracts, the ribcage expands and the contents of the abdomen are moved downward.

This results in a larger thoracic volume and negative pressure inside the thorax. Our lungs fill with air.

Exchange of gases.

The major function of the respiratory system is gas exchange between the external environment and an organism's circulatory system.

This exchange facilitates oxygenation of the blood with a concomitant removal of carbon dioxide and other gaseous metabolic wastes from the circulation.

The alveolar walls are extremely thin . These walls are composed of a single layer of epithelial cells close to the pulmonary capillaries.

The close proximity of these two cell types allows permeability to gases and  gas exchange.

Oxygen passes to the bloodstream and carbon dioxide leaves our lungs.

  Exhalation

During exhalation, expiratory muscles including the abdominal muscles and internal intercostal muscles, generate abdominal and thoracic pressure, which forces air out of the lungs.

   Carbon dioxide goes outside our body.

The vital function of   nutrition :

• Eating (nutrients and water)
• Breathing (oxygen)