Morphometric analysis of the postnatal development of the pig lung, with emphasis on alveoli and vessels, shows features of growth similar to man, but occurring at a much faster rate in the pig, which telescopes in the first 3 mo the changes seen in human childhood and adolescence. During the first weeks, arteries (birth to 2 wk) and alveoli (1-12 wk) increase in number, whereas increase in size continues until adulthood. Wall thickness decreases soon after birth in arteries 15-200 μm, and by 8 wk in those 200-1,000 μm. At this age the adult left ventricular predominance in weight is already present. Throughout growth the venous wall thickness does not change. Cardiopulmonary function studies in pigs, from 2 to 16 wk, show that, during the period of rapid postnatal lung growth, there is no change in tidal volume, dynamic compliance, and thoracic gas volume as related to body weight; right ventricular and pulmonary arterial pressures also remain unchanged, whereas pulmonary vascular resistance decreases during the 1st mo.
|Number of pages||12|
|Journal||Journal of Applied Physiology Respiratory Environmental and Exercise Physiology|
|Publication status||Published - 1 Dec 1978|