Thorax

LUNG

Bronchial Tree
The right main bronchus Wider More vertical

Bronchial Tree

Right main bronchus
Lobar bronchus
Segmental bronchus
trachea
Left main bronchus
Lobar bronchus

Bronchopulmonary Segment

Bronchopulmonary Segment
Segmental bronchus and its accompanying pulmonary artery branch 10 in each lung (some fuse in the left lobe)

Bronchopulmonary Segment

Position

Midclavicular line

Midaxillary line
Scapular line
Paravertebral line
Inferior border of the lung
Rib 6
Rib 8
Rib 10
T10
Inferior border of the pleura
Rib 8
Rib 10
Rib 11
T12

Lung

Base: the diaphragm Apex: rib I, into the root of the neck Surfaces: costal surface, mediastinal surface Borders: inferior border, anterior border, posterior border

Hilum and Root

Root of the lung (Anterior to posterior) superior pulmonary vein pulmonary artery main bronchus inferior pulmonary vein Pulmonary ligament

Right Lung

2 fissures, 3 lobes oblique fissure horizontal fissure superior lobe middle lobe inferior lobe

Right Lung

The root of the lung (superior to inferior) bronchus to superior lobe pulmonary artery bronchus to middle and inferior lobes superior pulmonary vein inferior pulmonary vein

Right Lung

Structures adjacent to the medial surface of the right lung the heart the inferior vena cava the superior vena cava the azygos vein the esophagus

Left Lung

1 fissure, 2 lobes oblique fissure superior lobe inferior lobe

Left Lung

The root of the lung (superior to inferior) pulmonary artery main bronchus superior pulmonary vein inferior pulmonary vein

Left Lung

Structures adjacent to the medial surface of the left lung the heart the aortic arch the thoracic aorta the esophagus

Lung

right
left

Pulmonary Vessels

Pulmonary arteries ← the pulmonary trunk Pulmonary veins → back into the left atrium

Bronchial Vessels

Bronchial arteries and veins interconnect within the lung with braches of the pulmonary arteries and veins“Nutritive” vascular system


Bronchial Vessels
Bronchial arteries ← thoracic aorta or one of its branches on the posterior surfaces of the bronchi and ramify in the lungs to supply pulmonary tissues.

Bronchial Vessels

Bronchial veins
Pulmonary veins or left atrium
Azygos veins or superior intercostal veins or hemiazygos veins

Innervation

Innervation
The vagus nerves constrict the bronchioles The sympathetic system dilate the bronchioles

Lymphatic drainage

tracheobronchial parasternal brachiocephalic nodes nodes nodes
right or left bronchomediastinal trunks
deep veins at the base of the neck, or right lymphatic trunk or thoracic duct



The lungs The lung is covered, over most of its surface, by a thin and smooth membrane, the visceral pleura. On the medial surface of the lung, at the hilum (L., a little thing) this smooth membrane reflects away from the surface of the lung and folds back to line the internal surface of the cavity in which the lung is suspended. This latter layer is known as the parietal pleura and covers the inner surface of the chest wall, the superior surface of the diaphragm, and the lateral surface of the mediastinum. Specialized regions of the parietal pleural membrane are named for the structures they cover.


The mediastinal pleura covers the lateral surface of the mediastinum. The diaphragmatic pleura covers the superior surface of the diaphragm. The costal pleura lines the internal surface of the ribcage. The most superior portion of the pleural membrane, the cervical pleura, or dome of the pleura, extends 1 to 2 cm into the neck above the level of the clavicle and first rib. All of these portions of the parietal pleura are, of course, continuous with each other. The visceral and parietal pleurae are continuous with each other at the hilum, where a slightly elongated "collar" of pleura forms. Encircled by this collar are the structures that connect the lung to the mediastinum: the pulmonary and bronchial vessels, the airways, nerves, lymphatics, and the connective tissue.

A small inferior extension of this pleural collar is known as the pulmonary ligament, and, in the living, it may be palpated during surgery as a firm shelf of tissue on the medial surface of the lung. The pleural cavity is the potential space between the visceral and parietal pleurae. Inferolaterally on each side of the chest, where the lateral edge of the diaphragm meets the chest wall, is the costodiaphragmatic (costophrenic) recess. This recess is very lucent (i.e., dark) on an x-ray when the lung expands fully to fill it; at expiration, however, the lung recedes upward and the diaphragm and chest wall move near to each other once again, and the lucency disappears.


If, however, a patient has blood or inflammatory fluid in the pleural cavity, the fluid flows down into this recess, and in such a patient's x-ray at inspiration the angle is "blunted" by the accumulated fluid. There is another normally widened area of the pleural cavity anterior to the heart, on the left side, known as the costomediastinal recess. It becomes lucent at inspiration when the lingula of the left lung expands into it.