اختبار

The lungs are situated so that one lies on each side of the mediastinum. They are therefore separated from each other by the heart and great vessels and other structures in the mediastinum. Each lung has a blunt apex, which projects upward into the neck for about (2.5 cm) above the clavicle; a concave base that sits on the diaphragm; a convex costal surface,which corresponds to the concave chest wall; and a concave mediastinal surface, which is molded to the pericardium and other mediastinal structures. At about the middle of this surface is the hilum, adepression in which the bronchi, vessels, and nerves thatform the root enter and leave the lung. The root of the lung is formed of structures that are entering or leaving the lung. It is made up of the bronchi,pulmonary artery and veins, lymph vessels, bronchial vessels, and nerves.