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.
Two atria and one ventricle make up the three-chambered heart of a snake. The right and left atria receive blood from the lungs and body, respectively, and pass it to the ventricle to be circulated again. Encased in a sac, called the pericardium, the heart is located at the branching of the bronchi.