Journal of Applied Physiology, Vol 63, Issue 5 1866-1870, Copyright © 1987 by American Physiological Society
Distribution of pores within alveoli in the human lung
M. Kawakami and T. Takizawa
Department of Medicine 1, Tokyo Women's Medical College, Japan.
Usually the wall opposite the orifice of alveoli has been used to study
interalveolar pores by scanning electron microscopy. To ascertain whether
biased results may be obtained from this, the distribution of pores within
alveoli was studied in human lungs. By the use of scanning electron
photomicrographs, the number, major axes of pores, and proportional area of
pores to the alveolar wall were estimated. The alveolar wall seen opposite
the orifice was defined as the bottom wall. Average number of pores per
alveolus was 13-21, and one-half of them was located in the bottom walls.
The average length of major axes was 7-19 micron, and average area
fractions were 0.8-5%. The distribution of the numerical density, area
fraction, and size of pores was uniform regardless of their location within
the alveolus and the size of alveoli. Thus pores can be compared using the
bottom walls of alveoli. This will facilitate the study of the effects of
age, smoking, and topography on pore size and frequency in humans.
