The parasympathetic system causes bronchoconstriction, whereas the sympathetic nervous system stimulates bronchodilation.
Reflexes such as coughing, and the ability of the lungs to regulate oxygen and carbon dioxide levels, also result from this autonomic nervous system control.
A pulmonary lobule is a subdivision formed as the bronchi branch into bronchioles.
Each lobule receives its own large bronchiole that has multiple branches.
The nerves then follow the bronchi in the lungs and branch to innervate muscle fibers, glands, and blood vessels.
Each lung is enclosed within a cavity that is surrounded by the pleura.
The right lung is shorter and wider than the left lung, and the left lung occupies a smaller volume than the right.
The cardiac notch is an indentation on the surface of the left lung, and it allows space for the heart (Figure 1). Each lung is composed of smaller units called lobes. The right lung consists of three lobes: the superior, middle, and inferior lobes.
In contrast, the parietal pleura is the outer layer that connects to the thoracic wall, the mediastinum, and the diaphragm.
The visceral and parietal pleurae connect to each other at the hilum.