scholarly journals X. The intracranial vascular system of sphenodon

1909 ◽  
Vol 200 (262-273) ◽  
pp. 403-426 ◽  
Keyword(s):  
Blood Vessels ◽  
Vascular System ◽  
Serial Sections ◽  
Cranial Cavity ◽  
The Subject ◽  
Intracranial Arteries ◽  
Arteries And Veins ◽  
The Brain ◽  
Complete Account

In the course of my investigations on the Pineal Apparatus of the Tuatara ( Sphenodon punctas ) I have found it desirable to make as complete a study as possible of the arrangement of the intracranial arteries and veins, of which no description has as yet been published. As any facts relating to the structure of Sphenodon are of more than usual interest, and as I hope to be able to give a more complete account of the subject than has yet been given for any reptile, I have decided to offer my results for publication as a separate memoir, without waiting for the completion of my work on the pineal organs. The blood-vessels have been investigated partly by dissection and partly by means of serial sections, and such completeness of detail as I have been able to attain is very largely due to the adoption of a method of fixing and hardening which I have found to have many advantages both for the study of the vascular system and of the brain itself. By this method the entire contents of the cranial cavity are fixed and hardened in situ , and are then in excellent condition either for dissection or for histological purposes. The application of the method in the case of Sphenodon is greatly facilitated by the fact that the brain does not occupy nearly the whole of the cranial cavity, a large subdural space being left, especially above the brain, across which numerous blood-vessels run, together with delicate strands of connective tissue which connect the dura mater with the pia .

scholarly journals The intracranial vascular system of sphenodon

1909 ◽  
Vol 81 (548) ◽  
pp. 290-291 ◽  
Keyword(s):  
Blood Vessels ◽  
Vascular System ◽  
Foramen Magnum ◽  
Body Cavity ◽  
The Body ◽  
Cephalic Vein ◽  
Special Method ◽  
Cranial Cavity ◽  
The Right ◽  
The Brain

This memoir contains a detailed description, with illustrations, of the intracranial blood-vessels of the Tuatara, of which no account has hitherto been published. The description is belived to be more complete than any hithero given for any reptile, and a considerable number of vessels are described which have not hithero been noted in Lacertilia. This comparative completeness of detail is largely due to the employment of a special method of investigation. By this method the entire contents of the cranial cavity are fixed and hardened in situ , and are then in excellent condition either for dissection or for histological purposes. The brain does not occupy nearly the whole of the cranial cavity, there being a very large subdural space (especially above the brain), across which many of the blood-vessels run, together with delicate strands of connective tissue which connect the dura mater with pia. The eyeballs are removed and an incision is made on each side in the cartilaginous wall which separates the cranial cavity from the orbit. Acetic bichromate of potash (made up according to the formula given by Bolles Lee) is injected in to the cranial cavity through these incision, and the entire animal, after opening the body cavity, is suspended in a large volume of the same fluid for about five days, and then graded up to 70 per cent. Alcohol. When the cranial cavity is now opened up the cerebral vessels are seen with extraordinary distinctness, although they have not been artifically injected. Futher details were made out by means of serial sections, both transverse and longitudinal, and both of the adult and of advanced embroyes (Stage S). In most respect the arrangement of the intracranical blood-vessels agrees with found in the Lacertilia, so far as these have been investigated, but there is an important difference in the fact that the posterior cephalic vein leaves the cranial cavity through the foramen jugulare and not through the foramen magnum, while a slightly more primitive condition is shown in the less complete union of the right and left halves of the basilar artery. Sphenodon makes some approach to the condition of the Chelonia in this latter respect, but differs conspicuously from this group in the fact that the circle of Willis is not completed anteriorly, as well as in the fact that no branch of the posterior cephalic vein leaves the cranial cavity through the foreman magnum. A very characteristic features of Sphenodon is the development of large transverse sinues resembling those of the crocodile, but these communicate with the extracranial vascular system in quite a different manner from that described by Rathke in the latter animal.

XVII. On the blood-vessels of mustelus antarcticus: a contribution to the morphology of the vascular system in the vertebrata

1886 ◽  
Vol 177 ◽  
pp. 685-732 ◽  
Keyword(s):  
Blood Vessels ◽  
Vascular System ◽  
Comparative Anatomy ◽  
Considerable Importance ◽  
Arteries And Veins ◽  
General Work ◽  
Accessible Form ◽  
Complete Account

The present inquiry was undertaken with a view of settling, if possible, one or two doubtful points in our knowledge of the vascular system of Fishes, and of giving, in an accessible form, a fairly complete account of the blood-vessels of a typical Selachian, since, as far as I am aware, this has not yet been done. The arteries and veins of the Skate are figured, for the most part very accurately, by Monro (16); the arteries of Raja and Torpedo are described and figured in detail by Hyrtl (11), and there are good general accounts of the vascular system in both orders of Plagiostomi in the works of Müller (17), Stannius (25), and Milne Edwards (14). By all these authors, however, several points of considerable importance are either missed or but slightly referred to, while others are more or less inaccurately described. In all the more modern text-books of comparative anatomy to which I have had access the vascular system of Fishes is very meagrely treated, the manuals of Owen (19), Huxley (10), Claus (4), Gegenbaur (7), Rolleston (24), Macalister (13), Günther (8), and Wiedersheim (26), adding little or nothing to the excellent though brief account in Stannius’s handbook just referred to. Indeed, the only general work I have seen which gives any important information not to be found in Stannius is Milne Edwards’s ‘Leçons,' in which the description of the vascular system, and especially of the arteries of Fishes, is full, and, like everything else in that invaluable book, admirably clear.

A ‘Hyaline’ Layer in the Skin of Squids

1997 ◽  
Vol 77 (4) ◽  
pp. 1247-1250 ◽  
Author(s):  
J.J. Madan ◽  
M.J. Wells
Keyword(s):  
Oxygen Uptake ◽  
Blood Vessels ◽  
Amorphous Material ◽  
Thick Layer ◽  
Extensive Literature ◽  
Potential Importance ◽  
Nervous Control ◽  
The Subject ◽  
The Brain

The skin of Loligo vulgaris and Illex illecebrosus contains a thick layer of amorphous material. In Loligo it lies above and in Illex below the chromatophore layer. We can find no mention of this layer in the considerable literature on squid skins despite its potential importance as a protection to underlying tissues and as a possible barrier to cutaneous oxygen uptake.Cephalopods have soft complicated skins. Embedded in the skin, most species have chromatophores, small bags of pigment that can be expanded by muscles that are under direct nervous control from the brain. There is an extensive literature on the physiology of chromatophores (Packard, 1988) and on their function in the behaviour of the animals (Hanlon & Messenger, 1996; Packard & Hochberg, 1977). Further cutaneous structures concerned in the determination of the colour of living cephalopods, the reflecting iridophores and leucophores (Cloney & Brocco, 1983), and the light generating photophores (Herring, 1988), have been the subject of a number of reports but other skin features such as the distribution of blood vessels have attracted little attention.

The Histopathological Criteria of Vascular Disturbances in the Brain.∗

1937 ◽  
Vol 83 (346) ◽  
pp. 509-509 ◽  
Author(s):  
Alfred Meyer
Keyword(s):  
Blood Vessels ◽  
Cardiac Disease ◽  
Vascular System ◽  
Head Injuries ◽  
Common Factor ◽  
Mental Deficiency ◽  
Vascular Lesions ◽  
Organic Lesion ◽  
Histological Appearance ◽  
The Brain

Vascular lesions, identical in appearance with the sequelae of organic diseases of the blood-vessels, have been found in a great variety of conditions (for instance in epilepsy, hypertension and cardiac disease, psychoses associated with infectious and toxic conditions, head injuries, certain groups of mental deficiency) in which no organic lesion of the blood-vessels themselves could be demonstrated. The theory has been put forward (Ricker, Spielmeyer and others) that these lesions owe their origin to functional disorder of the vascular system, and that this common factor accounts for the identity in histological appearance in spite of the profound ætiological differences.

scholarly journals Micrometer-resolution reconstruction and analysis of whole mouse brain vasculature by synchrotron-based phase-contrast tomographic microscopy

2021 ◽  
Author(s):  
Arttu Miettinen ◽  
Antonio Zippo ◽  
Alessandra Patera ◽  
Anne Bonnin ◽  
Sarah Shahmoradian ◽  
...  
Keyword(s):  
Blood Vessels ◽  
Mouse Brain ◽  
Nervous Tissue ◽  
Vascular System ◽  
Computational Method ◽  
Resolving Power ◽  
Topological Features ◽  
Parkinson’S Diseases ◽  
Branching Points ◽  
The Brain

Nervous tissue metabolism is mainly supported by the dense thread of blood vessels which mainly provides fast supplies of oxygen and glucose. Recently, the supplying role of the brain vascular system has been examined in major neurological conditions such as the Alzheimer's and Parkinson's diseases. However, to date, fast and reliable methods for the fine level microstructural extraction of whole brain vascular systems are still unavailable. We present a methodological framework suitable for reconstruction of the whole mouse brain cerebral microvasculature by X-ray tomography with the unprecedented pixel size of 0.65 μm. Our measurements suggest that the resolving power of the technique is better than in many previous studies, and therefore it allows for a refinement of current measurements of blood vessel properties. Relevant insights emerged from analyses characterizing the regional morphology and topology of blood vessels. Specifically, vascular diameter and density appeared non-homogeneously distributed among the brain regions suggesting preferential sites for high-demanding metabolic requirements. Also, topological features such as the vessel branching points were non-uniformly distributed among the brain districts indicating that specific architectural schemes are required to serve the distinct functional specialization of the nervous tissue. In conclusion, here we propose a combination of experimental and computational method for efficient and fast investigations of the vascular system of entire organs with submicrometric precision.

V.—Abnormalities in the Blood Vascular System of the Anura

1932 ◽  
Vol 57 (1) ◽  
pp. 179-224 ◽  
Author(s):  
Charles H. O'Donoghue
Keyword(s):  
Blood Vessels ◽  
Vascular System ◽  
Rana Temporaria ◽  
Abnormal Position ◽  
The Subject

It is a familiar experience for the teacher in charge of a class dissecting Rana temporaria to notice or have his attention directed to blood-vessels in an abnormal position or absent from the place where they were expected. Sometimes, perhaps too frequently, they are ignored; but they are of interest, not only in themselves, but also because they throw light on problems that have arisen in other lines of work. From time to time such abnormalities have been reported in R. temporaria and in other Anura, but the literature of the subject is scattered in different journals.

Cloning of the rat P2u receptor and its potential role in coronary vasodilation

1996 ◽  
Vol 270 (2) ◽  
pp. C570-C577 ◽  
Author(s):  
S. Godecke ◽  
U. K. Decking ◽  
A. Godecke ◽  
J. Schrader
Keyword(s):  
Blood Vessels ◽  
Rat Heart ◽  
Receptor Gene ◽  
Coding Region ◽  
Rat Hearts ◽  
Perfused Rat Hearts ◽  
Coronary Blood Vessels ◽  
The Brain ◽  
Isolated Perfused Rat Hearts

We cloned and sequenced the cDNA as well as the genomic DNA of the P2u receptor gene from the rat. The coding region of the gene is not interrupted by introns. P2u is expressed in a variety of rat organs with pronounced differences of expression intensities. Highest expression was found in liver and testis, while no expression could be detected in the brain. High P2u expression was found in primary microvascular endothelial cells from the rat heart, but not in cardiac myocytes. By in situ analysis, we localized P2u expression in epithelial cells of esophagus and bronchi. Functional analysis revealed that, in isolated perfused rat hearts, the P2u ligands UTP and ATP induce a pronounced vasodilation of coronary blood vessels. In contrast, UMP and uridine, the degradative products of UTP, act as potent vasoconstrictors. Our experiments suggest that, in the rat heart, endothelial P2u receptors are involved in the ATP/UTP-mediated vasodilation of coronary blood vessels.

scholarly journals I. On the blood-vessels of Mustelus antarcticus : a contribution to the morphology of the vascular system in the vertebrata

1886 ◽  
Vol 40 (242-245) ◽  
pp. 471-474
Keyword(s):  
Blood Vessels ◽  
Vascular System ◽  
Arteries And Veins

The paper describes in detail the arteries and veins of Mustelus antarcticus , comparing them with those of other elasmobranchs, and with the embryonic trunks of the vertebrata generally. As far as the author’s resources would allow, the synonymy of the principal vessels is given. The paper is illustrated by four quarto plates, and two diagrams in the text; the figures are, as a rule, made by combining the results of several dissections; the topographical relations of the chief vessels are shown in drawings of transverse sections of a frozen specimen.

Molecular cloning, functional analysis, and RNA expression analysis of connexin45.6: a zebrafish cardiovascular connexin

2004 ◽  
Vol 286 (5) ◽  
pp. H1623-H1632 ◽  
Author(s):  
Tara L. Christie ◽  
Rickie Mui ◽  
Thomas W. White ◽  
Gunnar Valdimarsson
Keyword(s):  
Gap Junctions ◽  
Cardiovascular System ◽  
Vascular System ◽  
Amino Acid Identity ◽  
Rt Pcr ◽  
Intercellular Coupling ◽  
Protein Subunits ◽  
Connexin Gene ◽  
The Brain

In the vertebrate cardiovascular system, gap junctions function in intercellular communication essential for both the coordinated propagation of the heartbeat and the control of vasomotor responses in the vascular system. Connexins, the protein subunits of gap junctions, are coded by a multigene family. In this study, a connexin gene (zfCx45.6), which exhibits 53% amino acid identity to chick Cx42, was cloned from zebrafish genomic DNA. With the use of the LN54 radiation hybrid panel, zfCx45.6 was mapped to zebrafish linkage group 9. Northern blots and RT-PCR revealed the presence of zfCx45.6 mRNA in the embryo before 2 h postfertilization (hpf) and then again beginning at about 12 hpf, after which time no major changes in relative expression levels were detected. In the adult, zfCx45.6 mRNA continued to be detected in the heart, as well as the brain, liver, and ovary, but not the lens. Whole mount in situ hybridization revealed zfCx45.6 mRNA was expressed at high levels in the major vessels of the entire embryo and in both the atrium and ventricle of the adult heart. Expression of zfCx45.6 channels in paired Xenopus oocytes produced high levels of intercellular coupling that was voltage sensitive. With the previous isolation of zebrafish Cx43 and Cx43.4, zebrafish orthologues have now been isolated for three of the four connexins expressed in the mammalian cardiovascular system.

Direct Observations of the Epitaxial Growth of Sputtered Ag on Si

1973 ◽  
Vol 31 ◽  
pp. 122-123
Author(s):  
J. S. Maa ◽  
Thos. E. Hutchinson
Keyword(s):  
Epitaxial Growth ◽  
Film Growth ◽  
Ion Beam ◽  
Ion Beam Sputtering ◽  
Microscopy Technique ◽  
Direct Observations ◽  
In Situ Electron Microscopy ◽  
Beam Sputtering ◽  
The Subject

The growth of Ag films deposited on various substrate materials such as MoS2, mica, graphite, and MgO has been investigated extensively using the in situ electron microscopy technique. The three stages of film growth, namely, the nucleation, growth of islands followed by liquid-like coalescence have been observed in both the vacuum vapor deposited and ion beam sputtered thin films. The mechanisms of nucleation and growth of silver films formed by ion beam sputtering on the (111) plane of silicon comprise the subject of this paper. A novel mode of epitaxial growth is observed to that seen previously.The experimental arrangement for the present study is the same as previous experiments, and the preparation procedure for obtaining thin silicon substrate is presented in a separate paper.

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