Trachea with the lungs and pulmonary vessels
In this specimen we can see the trachea, the lungs and the pulmonary vessels. The Trachea divides into two principal bronchi ‚Äì right and left. Each lung is divided into lobes- three on right side by the oblique and transverse fissures and two on left side by the oblique fissure. The principal bronchus on the right side divides into three secondary bronchi, one for each lobe i.e., the upper, middle and lower. On the left side, the principal bronchus divides into two secondary bronchi, for the upper and lower lobes. The lungs are conical in shape with an apex, base, three surfaces and three borders. The structures at the hilum of the lungs are identified here.
On the Right side (from above downwards): - Eparterial bronchus - Pulmonary artery - Hyparterial bronchus - Inferior pulmonary vein
On the Left side (from above downwards): - Pulmonary artery - Bronchus - Inferior pulmonary vein
The trachea (Latin, air vessel; also called the wind-pipe) is a 10-15 cm long tube situated in the lower part of the neck and superior mediastinum. Its upper under is continuous with the larynx at the level of C6 vertebra. It is made up of C-shaped cartilaginous rings (hyaline in nature and 16-20 in number) anteriorly. Posteriorly the gap is closed by a fibro-elastic membrane and contains trachealis muscle. At the level of the sternal angle (i,e, lower border of T4 vertebra) the trachea bifurcates into two principal bronchi.
The lungs are the paired respiratory organs situated in the pleural cavity. They aid in the oxygenation of the blood. Each lung is conical in shape with a rounded apex, a broad base or diaphragmatic surface, costal surface and medial surface separated by three borders. The right lung is divided into three lobes (upper, middle and lower) by two fissures (oblique and horizontal). The left lung is divided into two lobes (upper and lower) by an oblique fissure.
The pulmonary vessels are the pulmonary arteries and veins.
Pulmonary artery: The right and left pulmonary arteries arise as branches from the pulmonary trunk. The pulmonary trunk extends from the infundibulum of the right ventricle and conveys the deoxygenated blood to the lungs via the pulmonary arteries.
Pulmonary veins: They are four in number (two superior and two inferior). They carry oxygenated
The epartial bronchus or the upper lobe bronchus is the secondary bronchus of the upper lobe of the right lung. It arises above the level of the pulmonary artery
The hyparterial bronchus is a secondary bronchus that arises below the level of the pulmonary artery.