The development of the bronchopulmonary segments in human embryos of horizons xvii to xix

Wells, L. J.; Boyden, Edward A.

doi:10.1002/aja.1000950202

Cited by 44 publications

(20 citation statements)

References 13 publications

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“…The lungs of 11 patients who died between 1950 and 1978 were studied (Table 1). Cyanosis was noted within the first two days in four babies, within the first two months in a further four, at 5 months in case 7, and at 2 years in the remaining documented case (one case was undocumented).…”

Section: Methodsmentioning

confidence: 99%

Growth and development of pulmonary circulation in pulmonary atresia with ventricular septal defect and major aortopulmonary collateral arteries.

Haworth¹,

Macartney²

1980

Heart

157

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SUMMARY In 11 necropsy specimens of pulmonary atresia with ventricular septal defect and major aortopulmonary collateral arteries, central pulmonary arteries were present in all cases, supplied by collateral arteries which anastomosed with a lobar pulmonary artery or, less commonly, with a central pulmonary artery. These normally connected pulmonary arteries frequently perfused only a minority of bronchopulmonary segments. The remaining segments were connected to collateral arteries which, within the lung, were continuous with vessels which had the structure of normally connected vessels and branched with the pre-and intra-acinar airways in a normal manner to perfuse the alveolar capillary bed. These collateral arteries and the intrapulmonary vessels with which they anastomosed had no connection, either macroscopically or microscopically, with either the central pulmonary arteries or their branches within the lung. Irrespective ofthe type ofproximal connection, the segmental pulmonary arteries were generally abnormally small. Stenoses occurred in 58-8 per cent of collateral arteries, usually as a thick-walled narrowed muscular section between the aorta and lung. Microscopically, quantitative morphometric analysis showed that within the respiratory unit the pulmonary circulation had failed to grow normally in all save the youngest patient dying at 12 days of age. The structural changes were usually consistent with a reduction in pulmonary blood flow; only three cases contained any segments of lung showing structural evidence of pulmonary hypertension. These anatomical and histological findings are discussed in relation to the embryology, nomenclature, and natural history of pulmonary atresia with ventricular septal defect and major aortopulmonary collateral arteries. The structural findings provide a rational basis for the clinical management of this condition.The preoperative assessment of pulmonary atresia with ventricular septal defect and major aortopulmonary collateral arteries has been improved by selective catheterisation of the collateral arteries. Corrective surgery is now possible using valvebearing conduits to establish continuity between the right ventricle and pulmonary circulation. The management of this condition remains imperfect, however, mainly because the anatomy of the pulmonary circulation is poorly understood. Radiological, haemodynamic, and surgical studies often provide an incomplete picture of the source of pulmonary blood supply and the intrapulmonary arterial branching pattern. In addition, the structure of the pulmonary circulation at alveolar level determines pulmonary vascular resistance and

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Section: Methodsmentioning

confidence: 99%

Growth and development of pulmonary circulation in pulmonary atresia with ventricular septal defect and major aortopulmonary collateral arteries.

Haworth¹,

Macartney²

1980

Heart

157

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“…He also reported that the smaller lobes tended to be supplied by a single branch (Table 4). According to Boyden and Scannell (1948) and Wells and Boyden (1954), the apical segmental bronchus consists of apical and anterior subsegmental rami (Bla and 131b) and the posterior segmental bronchus consists of apical and posterior subsegmental rami (B3a and B3b). Since the abbreviation of the posterior segmental bronchus in Nomina Anatomica (1983) is B2, it would be necessary to convert it to the position of B2 from B3 in Boyden's (1952) figures and table.…”

Section: Bronchial Supply Of the Azygos Lobementioning

confidence: 99%

An Autopsy Case of Azygos Lobe and the Extra-pulmonary Course of the Bronchial Veins in Man

Chiba

Suzuki

Takahashi

et al. 1990

Okajimas Folia Anatomica Japonica

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Summary: The present case represents the second report of an aberrant azygos lobe, following Adachi's (1940) first case.The authors describe the characteristic features of an azygos lobe observed in the right lung of a 65-year-old man as well as the extra-pulmonary course of the bronchial arteries and veins. The literature on the azygos lobe reported in Japan and the extremely rare cases in which an azygos lobe has been found on the left side, are summarized.Upon dissecting the pulmonary parenchyma, it became clear that the azygos lobe was supplied by definitive segmental branches (B1a and B2a, A1a and A2a, and V1a and V2a) of the tracheobronchial tree and pulmonary vessels. The authors review and summarize the patterns of the segmental bronchi and vessels in the azygos lobe and also discuss the development of this anomaly.

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“…New branching patterns can arise by reiterative use of subroutines or new patterns of their deployment. Indeed, the limited developmental data available for human and pig provides evidence that at least domain branching and orthogonal bifurcation are used in other animals 20,21,43 . New branching patterns can also arise by local modifications of subroutines, like the increased number and altered positions of domain branches in Spry2 and shifty mutants, and the reduction of the standard four-domain structure to three domains for R.Ac.…”

Section: Evolution Of Branching Networkmentioning

confidence: 99%

The branching programme of mouse lung development

Metzger

Klein

Martin

et al. 2008

Nature

704

786

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Mammalian lungs are branched networks containing thousands to millions of airways arrayed in intricate patterns that are crucial for respiration. How such trees are generated during development, and how the developmental patterning information is encoded, have long fascinated biologists and mathematicians. However, models have been limited by a lack of information on the normal sequence and pattern of branching events. Here we present the complete three-dimensional branching pattern and lineage of the mouse bronchial tree, reconstructed from an analysis of hundreds of developmental intermediates. The branching process is remarkably stereotyped and elegant: the tree is generated by three geometrically simple local modes of branching used in three different orders throughout the lung. We propose that each mode of branching is controlled by a genetically-encoded subroutine, a series of local patterning and morphogenesis operations, which are themselves controlled by a more global master routine. We show that this hierarchical and modular program is genetically tractable, and it is ideally suited to encoding and evolving the complex networks of the lung and other branched organs.Many organs are composed of highly ramified tubular networks, each with a distinct architecture tailored to its physiological function. The bronchial tree of the human lung has over 10 5 conducting and 10 7 respiratory airways arrayed in an intricate pattern crucial for oxygen flow [1][2][3][4] . Classical studies of lung structure 5-8 raise the question of how the information required to generate a tree of such complexity is biologically encoded 9 . Individually configuring thousands or millions of branches would require a tremendous amount of patterning information, far more than is biologically plausible, to specify when and where each branch forms during development, and the size, shape, and direction of outgrowth of each branch. One possibility is that the process is not precisely controlled, for example if branching occurs randomly to fill available space. Another is that control is precise but coding is simplified by repeated use of a branching mechanism, as in Mandelbrot's fractal model and other elegant algorithms [10][11][12][13][14][15][16][17] . Even with these attractive models and recent progress in identifying lung development genes 18 , understanding of the program that directs branching remains rudimentary. This is largely due to the complexity of the bronchial tree, which makes it difficult to follow branching dynamics beyond the earliest events [19][20][21] . Although branching of the lung and other organs can occur in culture [22][23][24][25] , it is unlikely these recapitulate the full pattern. Here, we have determined the complete in vivo pattern of branching and branch lineage of the mouse bronchial tree, and show that it is generated using three geometrically distinct local modes of branching coupled in three different sequences. The branch lineage of the mouse bronchial treeThe bronchial tree develops by bran...

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The development of the bronchopulmonary segments in human embryos of horizons xvii to xix

Cited by 44 publications

References 13 publications

Growth and development of pulmonary circulation in pulmonary atresia with ventricular septal defect and major aortopulmonary collateral arteries.

Growth and development of pulmonary circulation in pulmonary atresia with ventricular septal defect and major aortopulmonary collateral arteries.

An Autopsy Case of Azygos Lobe and the Extra-pulmonary Course of the Bronchial Veins in Man

The branching programme of mouse lung development

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