scholarly journals Terminal bronchiole

2017 ◽  
Author(s):  
Tom Foster ◽  
James Ling
Keyword(s):  
Terminal Bronchiole

Branching pattern of airways and air spaces of a single human terminal bronchiole

1975 ◽  
Vol 38 (6) ◽  
pp. 983-989 ◽  
Author(s):  
J. E. Hansen ◽  
E. P. Ampaya ◽  
G. H. Bryant ◽  
J. J. Navin
Keyword(s):  
Young Adult ◽  
Polyurethane Foam ◽  
First Generation ◽  
Human Lung ◽  
Branching Pattern ◽  
Serial Sections ◽  
Adult Human ◽  
Three Generations ◽  
Terminal Bronchiole ◽  
Adult Human Lung

A polyurethane-foam enlarged reconstruction was made from serial sections of a portion of young adult human lung parenchyman. Study of the progeny of a terminal bronchiole disclosed three generations of respiratory bronchioles and an irregular branching pattern of eight generations of alveolar ducts. Sacs and alveoli arose from the lateral and distal aspects of all generations of ducts. There were an average of 3.5 alveoli per sac. Considering the terminal bronchiole as the first generation branch of the acinus, over 60 per cent of the alveoli counted and predicted were members of the 10–12th generations. The acinus contained one terminal bronchiole and approximately 14 respiratory bronchioles, 1,200–1,500 ducts, 2,500–4,500 sacs, and 14,000–20,000 alveoli.

Changes in airway length after unilateral pneumonectomy in weanling ferrets

1990 ◽  
Vol 68 (1) ◽  
pp. 187-192 ◽  
Author(s):  
K. K. Kirchner ◽  
J. T. McBride
Keyword(s):  
Quadratic Equation ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Cross Sectional ◽  
Peripheral Airways ◽  
Peripheral Airway ◽  
The Relationship ◽  
Bronchial Casts ◽  
Central Airway ◽  
Terminal Bronchiole

We have previously shown that airway cross-sectional area increases 15-20% after pneumonectomy in weanling ferrets by measuring bronchial casts. We have now reanalyzed these same casts to quantitate changes in airway length after pneumonectomy. In each cast the distance from each of 120 airways to the terminal bronchiole along its axial pathway was measured. The relationship between the logarithm of this distance and that of the fraction of the lobe subtended by an airway could be described by a quadratic equation with a correlation coefficient greater than 0.85. Subsegmental and more distal airways of postpneumonectomy animals were 33-47% longer than those of controls. Overall the main axial pathway of airways in the left lower lobes was 12% longer in operated animals, but this increase was primarily accounted for by an increase in the length of the more peripheral airways. Central airways were little if any longer in operated animals. After pneumonectomy in weanling ferrets, subsegmental and peripheral airway lengths increase to a greater degree than lung volume and airway cross-sectional area, whereas central airway lengths increase to a lesser extent if at all. The mechanisms responsible for this difference between central and intralobar compensatory airway growth are unknown.

New Insight into the Development of the Respiratory Acini in Rabbits: Morphological, Electron Microscopic Studies, and TUNEL Assay

2019 ◽  
Vol 25 (3) ◽  
pp. 769-785 ◽  
Author(s):  
Doaa M. Mokhtar ◽  
Manal T. Hussein ◽  
Marwa M. Hussein ◽  
Enas A. Abd-Elhafez ◽  
Gamal Kamel
Keyword(s):  
Tunel Assay ◽  
Second Phase ◽  
Type I ◽  
Apoptotic Cells ◽  
Clara Cells ◽  
Ciliated Cells ◽  
Blood Capillaries ◽  
Pulmonary Alveoli ◽  
Alveolar Septa ◽  
Terminal Bronchiole

AbstractThis study investigated the histomorphological features of developing rabbit respiratory acini during the postnatal period. On the 1st day of postnatal life, the epithelium of terminal bronchiole consisted of clear cells which intercalated between few ciliated and abundant non-ciliated (Clara) cells. At this age, the rabbit lung was in the alveolar stage. The terminal bronchioles branched into several alveolar ducts, which opened into atria that communicated to alveolar sacs. All primary and secondary inter-alveolar septa were thick and showed a double-capillary network (immature septa). The primitive alveoli were lined largely by type-I pneumocytes and mature type-II pneumocytes. The type-I pneumocytes displayed an intimate contact with the endothelial cells of the blood capillaries forming the blood–air barrier (0.90 ± 0.03 µm in thickness). On the 3rd day, we observed intense septation and massive formation of new secondary septa giving the alveolar sac a crenate appearance. The mean thickness of the air–blood barrier decreased to reach 0.78 ± 0.14 µm. On the 7th day, the terminal bronchiole epithelium consisted of ciliated and non-ciliated cells. The non-ciliated cells could be identified as Clara cells and serous cells. New secondary septa were formed, meanwhile the inter-alveolar septa become much thinner and the air–blood barrier thickness was 0.66 ± 0.03 µm. On the 14th day, the terminal bronchiole expanded markedly and the pulmonary alveoli were thin-walled. Inter-alveolar septa become much thinner and single capillary layers were observed. In the 1st month, the secondary septa increased in length forming mature cup-shaped alveoli. In the 2nd month, the lung tissue grew massively to involve the terminal respiratory unit. In the 3rd month, the pulmonary parenchyma appeared morphologically mature. All inter-alveolar septa showed a single-capillary layer, and primordia of new septa were also observed. The thickness of the air–blood barrier was much thinner; 0.56 ± 0.16 µm. TUNEL assay after birth revealed that the apoptotic cells were abundant and distributed in the epithelium lining of the pulmonary alveoli and the interstitium of the thick interalveolar septa. On the 7th day, and onward, the incidence of apoptotic cells decreased markedly. This study concluded that the lung development included two phases: the first phase (from birth to the 14th days) corresponds to the period of bulk alveolarization and microvascular maturation. The second phase (from the 14th days to the full maturity) corresponds to the lung growth and late alveolarization.

scholarly journals Bronchioalveolar stem cells derived from mouse-induced pluripotent stem cells promote airway epithelium regeneration

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Naoya Kawakita ◽  
Hiroaki Toba ◽  
Keiko Miyoshi ◽  
Shinichi Sakamoto ◽  
Daisuke Matsumoto ◽  
...  
Keyword(s):  
Stem Cells ◽  
Induced Pluripotent Stem Cells ◽  
Pluripotent Stem Cells ◽  
Airway Epithelium ◽  
Secretory Granules ◽  
Flow Cytometric Analysis ◽  
Lamellar Body ◽  
Alveolar Type ◽  
Induced Pluripotent ◽  
Terminal Bronchiole

Abstract Background Bronchioalveolar stem cells (BASCs) located at the bronchioalveolar-duct junction (BADJ) are stem cells residing in alveoli and terminal bronchioles that can self-renew and differentiate into alveolar type (AT)-1 cells, AT-2 cells, club cells, and ciliated cells. Following terminal-bronchiole injury, BASCs increase in number and promote repair. However, whether BASCs can be differentiated from mouse-induced pluripotent stem cells (iPSCs) remains unreported, and the therapeutic potential of such cells is unclear. We therefore sought to differentiate BASCs from iPSCs and examine their potential for use in the treatment of epithelial injury in terminal bronchioles. Methods BASCs were induced using a modified protocol for differentiating mouse iPSCs into AT-2 cells. Differentiated iPSCs were intratracheally transplanted into naphthalene-treated mice. The engraftment of BASCs into the BADJ and their subsequent ability to promote repair of injury to the airway epithelium were evaluated. Results Flow cytometric analysis revealed that BASCs represented ~ 7% of the cells obtained. Additionally, ultrastructural analysis of these iPSC-derived BASCs via transmission electron microscopy showed that the cells containing secretory granules harboured microvilli, as well as small and immature lamellar body-like structures. When the differentiated iPSCs were intratracheally transplanted in naphthalene-induced airway epithelium injury, transplanted BASCs were found to be engrafted in the BADJ epithelium and alveolar spaces for 14 days after transplantation and to maintain the BASC phenotype. Notably, repair of the terminal-bronchiole epithelium was markedly promoted after transplantation of the differentiated iPSCs. Conclusions Mouse iPSCs could be differentiated in vitro into cells that display a similar phenotype to BASCs. Given that the differentiated iPSCs promoted epithelial repair in the mouse model of naphthalene-induced airway epithelium injury, this method may serve as a basis for the development of treatments for terminal-bronchiole/alveolar-region disorders.

Three-dimensional reconstruction of the rat acinus

1987 ◽  
Vol 63 (2) ◽  
pp. 785-794 ◽  
Author(s):  
R. R. Mercer ◽  
J. D. Crapo
Keyword(s):  
Average Distance ◽  
Quantitative Description ◽  
Three Dimensional ◽  
Outer Diameter ◽  
Small Airways ◽  
Branching Pattern ◽  
Diffusion Limitations ◽  
Dimensional Reconstruction ◽  
Alveolar Duct ◽  
Terminal Bronchiole

This study provides a quantitative description of the small airways and alveolar duct-alveolar architecture of the rat lung. To accomplish this, quantitative three-dimensional reconstructions were made of small airways, the alveolar duct system, and alveoli. The branching pattern of the small airways immediately proximal to the alveolar ducts varied significantly. For example, the number of bronchiole-alveolar duct junctions per parent bronchus (terminal bronchiole) ranged from two to six. The number of bronchiole-alveolar duct junctions per lung was 7,280 +/- 250 (mean +/- SE). The general shape of the ventilatory unit arising from each bronchiole-alveolar junction was that of a space-filling sphere with an outer diameter of 1,490 +/- 130 microns. The average distance from the bronchiole-alveolar duct junction to alveoli at the end of the alveolar sac termination was 1,290 +/- 100 microns. Numerous trifurcations were found in the branching pattern of the alveolar ducts. The branching of the alveolar ducts did not fit a regular dichotomous pattern. The volume of the terminal branches (alveolar sacs) accounted for 64 +/- 5% of the volume of the ventilatory unit. Both of these factors, the pattern of branching and the substantial volume distributed in the most peripheral branches, contribute to the uniform distribution of gas within the ventilatory unit and thus minimize potential diffusion limitations to gas exchange.

Alterations in alveolar clearance after 4-ipomeanol-induced necrosis of Clara and ciliated cells in the terminal bronchiole of the rat

1985 ◽  
Vol 80 (3) ◽  
pp. 534-541 ◽  
Author(s):  
Paul E. Newton ◽  
John R. Latendresse ◽  
David R. Mattie ◽  
Chris Pfledderer
Keyword(s):  
Ciliated Cells ◽  
Terminal Bronchiole
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