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.
Trace the pathway of air from the trachea to the respiratory zone. Trachea, to primary bronchi, to secondary bronchi, to tertiary bronchi, to smaller bronchi, to bronchioles, to terminal bronchioles, to respiratory zone. 7. Describe the difference between bronchi and bronchioles in terms of smooth muscle and cartilage. Bronchi have rings of cartilage that keep them open.