Respiratory system

Human Respiratory system

The human respiratory organs are shown in the following diagram.
Overall passage of air in human is as follows:
Nostrils-->Pharynx-->trachea-->Bronchi-->Bronchioles-->Alveoli-->Cells-->Blood.
Breathing rate in human = 18-20/min.Transportation of oxygen takes place by haemoglobin of blood.Whereas transportation of only 10-20% carbon dioxide takes place by haemoglobin of blood.