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.
The bronchial tree is an essential part of the respiratory system. It consists of several interacting structures, such as the bronchi, bronchioles, and alveoli. These structures work together to provide a network system between the lungs and the trachea.Without this system, a person could not breathe properly.he primary bronchi also branch off, forming two smaller bronchial tubes known as the lobar bronchi, or secondary bronchi. There are three lobar bronchi on the right side and two on the left. The bronchiole treeâs parts continue reducing in size as these secondary bronchi become smaller tubes known as the bronchioles.