ABSTRACT
This chapter presents basic principles and current perspectives on lung devel-
opment, growth, and repair. Processes of injury described in subsequent chap-
ters must be viewed in the context of these factors. Throughout life, the lungs are a dynamic organ system that attempts to adapt to stress and to repair injury
to cells and tissue.Dependingon the circumstances, these processes of adapta-
tion and repair can mitigate pulmonary damage or exacerbate the progression
of injury.Many of the phenomena occurring during pulmonary adaptation and
repair recapitulate those involved in growth and development. This chapter
introduces basic elements of lung structure, embryology, and cellular specifica-
tion, including the effects of key transcription factors, growth factors, and
physical forces. Coverage includes fundamental information on alveolarization, the growth of gas exchange tissue, and the pulmonary capillary bed. A
description of relevant congenital abnormalities that lead to pulmonary hypo-
plasia is also provided. Concepts of pulmonary remodeling and repair perti-
nent to both prenatal and postnatal events are introduced, and their
relevance and importance for specific aspects of acute and chronic lung injury
are then detailed further in following chapters.
