Occupational Safety and Health Administration. 1  Department of Labor, Labor Department, DoL, Labor - the federal department responsible for promoting the working conditions of wage earners in the United States; created in 1913.
The oxygen and carbon dioxide exchange take place in the alveoli. Primary bronchi are located on the upper portion of the lungs, secondary bronchi is located at the center of the lungs and tertiary bronchi is located near bottom of the organs above the bronchioles.
One of the two large branches of the trachea. The trachea divides opposite the third thoracic vertebra into the right and left main bronchi. The point of division, called the carina trachea, is the site where foreign bodies too large to enter either bronchus would rest after passing through the trachea. The right bronchus is shorter and more vertical than the left one. After entering the lung each bronchus divides further and terminates in bronchioles.