The bronchi & subdivisions

 

** The bronchi & subdivisions.

*In general:

The respiratory air tubes branch and branch again[about 23 times], and they are called Respiratory tree…  or bronchial tree.

There by, In conducting zone; the trachea divides to form the right & the left main bronchi, Each bronchus runs obliquely in the mediastinum. The right main bronchus is shorter and more vertical than the Left One…

So, each main bronchus subdivide into secondary bronchi, three on the right & two on the left ..and then into tertiary bronchi, which then divide into smaller and smaller until the passages smaller than 1mm in diameter, and so called: bronchioles and then into 0.5mm in diameter..{Terminal bronchioles}…It is where the Supportive cartilage lost at the level of “0.5mm” and changed into smooth muscle fiber & Connective tissue, and then develop into respiratory zone.