Anatomy Atlases(tm) : A digital library of anatomy information

Home | About | FAQ | Reviews | Search

Anatomy Atlases: Atlas of Microscopic Anatomy: Section 1 - Cells Atlas of Microscopic Anatomy: Section 11 - Respiratory System

Plate 11.230 Alveolus

Ronald A. Bergman, Ph.D., Adel K. Afifi, M.D., Paul M. Heidger, Jr., Ph.D.
Peer Review Status: Externally Peer Reviewed


ALVEOLUS

Plate 11.230 Alveolus

Rat, glutaraldehyde-osmium fixation, toluidine blue stain, 1416 x.

Refer to Figure 11A which can be used in conjunction with this plate in order to follow the structural changes that occur from the respiratory bronchiole to alveolar ducts to alveolar sacs where gaseous exchange takes place.

The partition between adjacent alveoli is shown in this plate. Note that capillaries form a major part of the partition, the very thin alveolar wall and the alveolar cells. The alveolar wall has been shown by electron microscopy to be composed of an epithelial cell (Type I or Type II), basement membrane (basal lamina), and an endothelial cell. The Type II alveolar cells (also known as great alveolar cells or septal cells) are cuboidal in shape and appear to have empty vacuoles in their cytoplasm. The vacuoles, as shown by electron microscopy, frequently contain osmiophilic bodies with concentric lamellae (cytosomes). Cytosomes are believed to contribute to the pulmonary surfactant that coats the alveolar epithelium in order to reduce the surface tension and keep the alveoli from collapsing. Type I, squamous alveolar cells constitute 97 per cent of the respiratory epithelium at the alveolar level. The remaining 3 per cent are Type II, great alveolar cells, which produce the surfactant. Through the alveolar wall, gaseous exchange takes place between blood and air.

Next Page | Previous Page | Section Top | Title Page


Home | About Us | FAQ | Reviews | Contact Us | Search

Anatomy Atlases is curated by Michael P. D'Alessandro, M.D. and Ronald A. Bergman, Ph.D.

Please send us comments by filling out our Comment Form.

All contents copyright © 1995-2017 the Author(s) and Michael P. D'Alessandro, M.D. All rights reserved.

"Anatomy Atlases", the Anatomy Atlases logo, and "A digital library of anatomy information" are all Trademarks of Michael P. D'Alessandro, M.D.

Anatomy Atlases is funded in whole by Michael P. D'Alessandro, M.D. Advertising is not accepted.

Your personal information remains confidential and is not sold, leased, or given to any third party be they reliable or not.

The information contained in Anatomy Atlases is not a substitute for the medical care and advice of your physician. There may be variations in treatment that your physician may recommend based on individual facts and circumstances.

URL: http://www.anatomyatlases.org/