Bronchial Vasculature: The Other Pulmonary Circulation

2009 ◽  
pp. 217-227 ◽  
Author(s):  
Elizabeth Wagner
1968 ◽  
Vol 46 (2) ◽  
pp. 175-178 ◽  
Author(s):  
Pierre Biron ◽  
Philippe Meyer ◽  
Jean-Claude Panisset

The extraction of α-angiotensin and its aminopeptidase-resiistant analogue β-angiotensin by the pulmonary, hepatoportal, femoral, and renal vascular beds was studied in normal anesthetized dogs and rats by comparing the systemic pressor responses to infusions into the afferent and efferent vessel of each organ. The extraction percentage of both peptides by the pulmonary circulation was negligible whereas it averaged 70% for α-angiotensin and 63% for the β-analogue in the other three systemic vascular beds studied. It is concluded that the main process responsible for the clearing of angiotensin from the systemic circulation is not the activity of circulating angiotensinases but rather occurs in the tissues.


1927 ◽  
Vol 46 (5) ◽  
pp. 819-837 ◽  
Author(s):  
Richmond L. Moore

1. Cutting one vagus nerve, while recording the pulmonary ventilation of each lung separately, has no unique effect on the ventilation of the denervated lung. Both lungs respond to unilateral vagotomy by an equivalent slowing and deepening of respiratory movement. 2. When the bronchus to one lung is blocked the first effect is a slowing and deepening of the respiratory movements recorded by the opposite lung. As oxygen want develops these movements become rapid and shallow. 3. With a combination of these two conditions, i.e., when the bronchus to one lung is blocked and its vagus nerve is severed, the pulmonary ventilation recorded by the opposite lung exhibits the same changes as may result from unilateral vagotomy alone, unaccompanied by occlusion of the bronchus. 4. From these facts it may be concluded that the slowing and deepening of breathing which follows unilateral vagotomy does not depend for its occurrence upon the passage of air in and out of the bronchus of the lung whose vagus nerve has been sectioned. 5. The slowing of respirations after occlusion of the bronchus to one lung and section of the corresponding vagus nerve still occurs even though the phrenic nerve on the same side has been divided. This indicates that the slowing of respirations following unilateral vagotomy does not depend on the movements of the diaphragm on the side of vagal section. 6. When the pulmonary artery to one lung has been ligated and the vagus nerve on the same side cut, the response of the other lung is the same as has been described, namely, its respiratory movements become slower and deeper. This is taken as evidence that the results of unilateral vagotomy are not dependent upon an intact pulmonary circulation. 7. The general conclusions from these experiments are that the slowing and deepening of respirations following unilateral vagotomy do not depend upon: (a) Passage of air in and out of the trachea. (b) Expansion and collapse of the lung. (c) Existence of a normal pulmonary circulation in the vagotomized lung. (d) Normal fluctuations in alveolar carbon dioxide tension, (e) Contraction and relaxation of the diaphragm on the side of vagotomy. 8. The slowing and deepening of respirations, alluded to, may be presumed to indicate that a normal reflex (the Hering-Breuer reflex) has been interrupted. Since this interruption occurs in spite of all the conditions enumerated under Paragraph 7, we must conclude that none of these conditions is essential to the existence of this reflex.


1988 ◽  
Vol 62 (03) ◽  
pp. 411-419 ◽  
Author(s):  
Colin W. Stearn

Stromatoporoids are the principal framebuilding organisms in the patch reef that is part of the reservoir of the Normandville field. The reef is 10 m thick and 1.5 km2in area and demonstrates that stromatoporoids retained their ability to build reefal edifices into Famennian time despite the biotic crisis at the close of Frasnian time. The fauna is dominated by labechiids but includes three non-labechiid species. The most abundant species isStylostroma sinense(Dong) butLabechia palliseriStearn is also common. Both these species are highly variable and are described in terms of multiple phases that occur in a single skeleton. The other species described areClathrostromacf.C. jukkenseYavorsky,Gerronostromasp. (a columnar species), andStromatoporasp. The fauna belongs in Famennian/Strunian assemblage 2 as defined by Stearn et al. (1988).


1967 ◽  
Vol 28 ◽  
pp. 207-244
Author(s):  
R. P. Kraft

(Ed. note:Encouraged by the success of the more informal approach in Christy's presentation, we tried an even more extreme experiment in this session, I-D. In essence, Kraft held the floor continuously all morning, and for the hour and a half afternoon session, serving as a combined Summary-Introductory speaker and a marathon-moderator of a running discussion on the line spectrum of cepheids. There was almost continuous interruption of his presentation; and most points raised from the floor were followed through in detail, no matter how digressive to the main presentation. This approach turned out to be much too extreme. It is wearing on the speaker, and the other members of the symposium feel more like an audience and less like participants in a dissective discussion. Because Kraft presented a compendious collection of empirical information, and, based on it, an exceedingly novel series of suggestions on the cepheid problem, these defects were probably aggravated by the first and alleviated by the second. I am much indebted to Kraft for working with me on a preliminary editing, to try to delete the side-excursions and to retain coherence about the main points. As usual, however, all responsibility for defects in final editing is wholly my own.)


1967 ◽  
Vol 28 ◽  
pp. 177-206
Author(s):  
J. B. Oke ◽  
C. A. Whitney

Pecker:The topic to be considered today is the continuous spectrum of certain stars, whose variability we attribute to a pulsation of some part of their structure. Obviously, this continuous spectrum provides a test of the pulsation theory to the extent that the continuum is completely and accurately observed and that we can analyse it to infer the structure of the star producing it. The continuum is one of the two possible spectral observations; the other is the line spectrum. It is obvious that from studies of the continuum alone, we obtain no direct information on the velocity fields in the star. We obtain information only on the thermodynamic structure of the photospheric layers of these stars–the photospheric layers being defined as those from which the observed continuum directly arises. So the problems arising in a study of the continuum are of two general kinds: completeness of observation, and adequacy of diagnostic interpretation. I will make a few comments on these, then turn the meeting over to Oke and Whitney.


1966 ◽  
Vol 24 ◽  
pp. 337
Author(s):  
W. Iwanowska

A new 24-inch/36-inch//3 Schmidt telescope, made by C. Zeiss, Jena, has been installed since 30 August 1962, at the N. Copernicus University Observatory in Toruń. It is equipped with two objective prisms, used separately, one of crown the other of flint glass, each of 5° refracting angle, giving dispersions of 560Å/mm and 250Å/ mm respectively.


2020 ◽  
Vol 43 ◽  
Author(s):  
Philip Pettit

Abstract Michael Tomasello explains the human sense of obligation by the role it plays in negotiating practices of acting jointly and the commitments they underwrite. He draws in his work on two models of joint action, one from Michael Bratman, the other from Margaret Gilbert. But Bratman's makes the explanation too difficult to succeed, and Gilbert's makes it too easy.


1999 ◽  
Vol 173 ◽  
pp. 249-254
Author(s):  
A.M. Silva ◽  
R.D. Miró

AbstractWe have developed a model for theH2OandOHevolution in a comet outburst, assuming that together with the gas, a distribution of icy grains is ejected. With an initial mass of icy grains of 108kg released, theH2OandOHproductions are increased up to a factor two, and the growth curves change drastically in the first two days. The model is applied to eruptions detected in theOHradio monitorings and fits well with the slow variations in the flux. On the other hand, several events of short duration appear, consisting of a sudden rise ofOHflux, followed by a sudden decay on the second day. These apparent short bursts are frequently found as precursors of a more durable eruption. We suggest that both of them are part of a unique eruption, and that the sudden decay is due to collisions that de-excite theOHmaser, when it reaches the Cometopause region located at 1.35 × 105kmfrom the nucleus.


1975 ◽  
Vol 26 ◽  
pp. 395-407
Author(s):  
S. Henriksen

The first question to be answered, in seeking coordinate systems for geodynamics, is: what is geodynamics? The answer is, of course, that geodynamics is that part of geophysics which is concerned with movements of the Earth, as opposed to geostatics which is the physics of the stationary Earth. But as far as we know, there is no stationary Earth – epur sic monere. So geodynamics is actually coextensive with geophysics, and coordinate systems suitable for the one should be suitable for the other. At the present time, there are not many coordinate systems, if any, that can be identified with a static Earth. Certainly the only coordinate of aeronomic (atmospheric) interest is the height, and this is usually either as geodynamic height or as pressure. In oceanology, the most important coordinate is depth, and this, like heights in the atmosphere, is expressed as metric depth from mean sea level, as geodynamic depth, or as pressure. Only for the earth do we find “static” systems in use, ana even here there is real question as to whether the systems are dynamic or static. So it would seem that our answer to the question, of what kind, of coordinate systems are we seeking, must be that we are looking for the same systems as are used in geophysics, and these systems are dynamic in nature already – that is, their definition involvestime.


1976 ◽  
Vol 32 ◽  
pp. 577-588
Author(s):  
C. Mégessier ◽  
V. Khokhlova ◽  
T. Ryabchikova

My talk will be on the oblique rotator model which was first proposed by Stibbs (1950), and since received success and further developments. I shall present two different attempts at describing a star according to this model and the first results obtained in the framework of a Russian-French collaboration in order to test the precision of the two methods. The aim is to give the best possible representation of the element distributions on the Ap stellar surfaces. The first method is the mathematical formulation proposed by Deutsch (1958-1970) and applied by Deutsch (1958) to HD 125248, by Pyper (1969) to α2CVn and by Mégessier (1975) to 108 Aqr. The other one was proposed by Khokhlova (1974) and used by her group.


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