The main function of the respiratory system is to supply the blood with oxygen. We inhale oxygen and exhale carbon dioxide. Respiration happens when you breath in oxygen then the exchange of gases between the blood and tissues.
The main organs are the pharynx, nose, trachea, bronchi, epiglottis, larynx, and lungs. The passage of air goes through the nose, pharynx, trachea, bronchi. Then the air goes through the epiglottis and larynx the into the lungs. After that it is released as carbon dioxide.
Levels of Organazation
Cell- Epithelial cells
Tissue- Epithelial tissue
Organ- Lungs, nose
Organ System- Respiratory System