pulmonary interlobular septum

The pulmonary interlobular septum is a connective tissue partition containing blood vessels and lymphatics that separates adjacent pulmonary lobules.

These septa are located at the periphery of the lungs, forming the visible polygonal boundaries that demarcate individual secondary pulmonary lobules on the lung surface.

The septa provide structural support and contain pulmonary arteries, veins, and lymphatic vessels that distribute throughout the lung parenchyma.

The septa are continuous with the visceral pleura, connecting adjacent lobules and containing branches of the pulmonary and bronchial circulations.

Thickening of interlobular septa is a classic radiological sign of pulmonary edema, lymphangitis carcinomatosa, or pneumoconiosis, aiding in diagnosis of diffuse lung disease.