Respiration is a process where we inhale and exhale air while breathing. The respiratory system can be divided into tow functional portions
- The upper respiratory tract/ conducting zone
-the Lower respiratory tract/respiratory zone
The upper respiratory tract/conducting zone have al the passageways from where the air passes into the external environment. The passageways begin with the nares (nostrils) of the nose that open into the nasophrynx (nasal cavity). The nasal passage filters the air and makes it warm and moist and provides resonance to the speech. The nasophrynx opens behind the oral cavity into the oropharnynx. The oropharnyx then moves to larnygopharnyx and empties into the larynx, which is the voice box that contains vocal chords.
The vocal chord passes through the glottis and connects to the trachea/wind pipe. All these organs in the external respiration subsystem make up the conducting zone. When the air moves through the conducting zone it is cleaned, humidified and warmed as it does not harm the delicate organ it passes through.
Lower respiratory tract or respiratory zone is the site of gas exchange in the lungs. The respiratory tract is made up of respiratory bronchioles, alveolar ducts, alveoli and the multi-lobulated sacs these entire make up lungs and where most of the gas exchange occurs.