26.8 : 肺的大体解剖学

Enclosed within the ribcage, the lungs are cone-shaped organs in the thoracic cavity. Their apex lies beneath the clavicle, and the base sits on the diaphragm.

They are enveloped by the pleurae and connected to the mediastinum via vascular and bronchial links, known as the lung root.

Each lung features a hilum on the mediastinal surface, acting as an entry and exit point for various vessels, bronchi, and nerves.

The right lung is larger than the left lung, which has a cardiac notch to house the heart.

When seen laterally, the left lung is divided into superior and inferior lobes by the oblique fissure, while the right lung is split into superior, middle, and inferior lobes by the oblique and horizontal fissures.

Each lobe contains several bronchopulmonary segments, separated by connective tissue septa. The right lung has ten segments, while the left lung has 8 to 10.

These bronchopulmonary segments are further divided into smaller compartments called lobules, visible as hexagonal structures at the surface of the lung.