The pulmonary lobule as a whole: a systemic approach to lobular pathology.

A systemic approach to the pulmonary lobule in health and disease is attempted. There are emphasized the lobule definition, structure and functions (respiratory, metabolic, defensive), the program of lobular structures, their relation ways, their capacity of growth and regeneration, all contributing to the relative independence and autonomy of pulmonary lobules and to their behaviour as wholes. Taking into account the characters of pulmonary lobules in health, their pathological involvement is analysed on human and experimental materials, pointing out the importance of the aerogenic component of pathogenesis in determining the first phases of lung diseases, and of the true pulmonary characters of lesions, in comparison with those induced by the parenteral penetration of agents.