Let us briefly understand the structure and the function of the lungs. The lungs are two cone-shaped vital organs on either side of the chest, as shown in the figure. Air, which we breathe through the nose, enters into the lungs through the air-tube (called Trachea) which bifurcates into two tubes, each going to the respective lungs. Each of the bronchus (plural bronchi) branches into multiple, numerous small tubes called bronchioles. The bronchioles lead to terminal sacs called alveoli. The air eventually passes through the bronchioles to the alveoli to exchange carbon dioxide (CO2) with Oxygen in return.
In the normal circumstances, there is a clear passage in the bronchi and the bronchioles facilitating effortless breathing process. In case of the asthmatic episode, due to certain factors, the bronchi and the bronchioles go into 'spasm' leading to obstructed air passage (as shown in figure II), not allowing the oxygen to go across. This is a typical phenomenon of the acute asthmatic episode. So, asthmatic bronchitis is nothing but a disorder of the respiratory system whereby the lung tubes meet with episodic or chronic episodes of spasms, where the precipitating cause might differ from patient to patient and the frequency of attacks, the duration of attack as well as the intensity of the attack could vary from child to child.So, asthmatic bronchitis is nothing but a disorder of the respiratory system whereby the lung tubes meet with episodic or chronic episodes of spasms, where the precipitating cause might differ from patient to patient and the frequency of attacks, the duration of attack as well as the intensity of the attack could vary from child to child.