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.
They have a structure like that of the trachea, in that they comprise tubes supported by cartilage rings, but are smaller in diameter. The point at which the trachea divides into the left and right primary bronchus is known as the carina, and it's located just above the heart.nswer by Brandoneson. Confidence votes 19. The two branches of the trachea are called the bronchi (singuar bronchus). The left and right primary bronchi connect the trachea to the bronchioles and carry air into the lungs.