scholarly journals STROKE

2006 ◽  
Vol 12 (02) ◽  
pp. 114-117
Author(s):  
ASAD ALI ◽  
AHMAD DANYAL ◽  
AFTAB TURABI
Keyword(s):  
Subarachnoid Hemorrhage ◽  
Vascular System ◽  
Medical Problem ◽  
The Body ◽  
Cerebral Lesion ◽  
Cerebral Function ◽  
Careful Monitoring ◽  
Who Criteria ◽  
The Brain

Stroke was defined according to WHO criteria as rapidly developingsymptoms and / or signs of focal and at times global loss of cerebral function with no apparent cause other than thatof vascular disease1. Stroke is grossly divided into either2 1). Thrombotic. 2). Embolic. 3).Hemorrhagic type (Whichmay be either intra cerebral bleed or subarachnoid hemorrhage). The brain, like other organs of the body, requires anadequate vascular system in order to supply it with nutrients and oxygen and to remove metabolic wastes and carbondioxide. Stabilization of medical problem with careful monitoring, and active prevention and timely management ofsecondary complications are of the utmost important for reducing stroke morality rates and avoiding further ischemicbrain injury. For the ischemic cerebral lesion itself, as yet no treatment or combination of treatment has beenestablished to be universally effective3. However, current studies allow for the following 5 potential therapeutic areasto be identified.

Physiology in Relation to Psychological Medicine

1928 ◽  
Vol 74 (307) ◽  
pp. 647-652
Author(s):  
B. A. McSwiney
Keyword(s):  
Nervous System ◽  
Normal Activity ◽  
Voluntary Contraction ◽  
The Body ◽  
Cerebral Function ◽  
Physiological Factors ◽  
Quantitative Measurements ◽  
Psychological Medicine ◽  
Spinal Animal ◽  
The Brain

An invitation to address a gathering of medical psychologists is, to the physiologist, a great temptation, and on such occasions he is apt to leap into the whirlpools of psychology in an attempt to explain the workings of the brain by hypotheses based, alas, on insufficient evidence. The paucity of information on cerebral function in physiological text-books has an explanation. Our lack of knowledge is due to the absence of available methods for investigating the normal activity of the higher nerve centres. Explanations are too often advanced without a due appreciation of the function of the lower nervous system in bringing about the exquisite co-ordination and relationship that exists between the different areas and organs of the body. This function is well exemplified in the reciprocal innervation of which we have evidence with every normal voluntary contraction. The difficulties of investigation have their root in the complexity of the reactions of an animal endowed with a well-developed cerebral cortex, compared with those seen in the lower types of life, or in the spinal animal. It must be clear that if our knowledge of the physiological factors controlling mental activity is to advance, the physiologist must continue to make measurements, accurate, quantitative measurements, if possible, on structures which he can control, and on preparations in which he is able to isolate the disturbing factors, and from these results and conclusions to construct by slow degrees a knowledge and understanding of the nervous system.

scholarly journals On the decussation of fibres at the junction of the medulla spinalis with the medulla oblongata

1843 ◽  
Vol 4 ◽  
pp. 71-72
Keyword(s):  
Medulla Oblongata ◽  
Royal Society ◽  
The Body ◽  
Cerebral Lesion ◽  
Common Occurrence ◽  
Satisfactory Explanation ◽  
Actual Structure ◽  
Spinal Marrow ◽  
Motor Columns ◽  
The Brain

The author first alludes to what usually happens in affections of the brain, namely, that the loss of voluntary power and of sensation, manifest themselves in the opposite side of the body to that in which the cerebral lesion exists, a fact which has been attempted to be explained by the crossing of the fibres at the junction of the medulla oblongata with the anterior or motor columns of the medulla spinalis ; but such a structure, he observes, affords no explanation of the loss of sensation. The author then, referring to the communication of Sir Charles Bell to the Royal Society, in the year 1835, describing a decussation connected with the posterior columns, or columns of sensation, mentions that the accuracy of these dissections was doubted by Mr. Mayo and other eminent anatomists. The author proceeds to state that the symptoms of cerebral lesion do not always take place on the opposite side of the body to that in which the lesion of the brain exists, but that they occur sometimes on the same side; that the loss of power and of sensation, although confined to the same side, may exist in either the upper or the lower extremity; but that both are not necessarily implicated; and that, in fact, cases occur where there are marked deviations from what may be considered the more common occurrence. Having observed such cases, and not being aware of any satisfactory explanation, the author examined with care the continuation upwards of the anterior and posterior columns of the spinal marrow into the medulla oblongata and found that the decussation at the upper part of the spinal marrow belonged in part to the columns for motion, and in part to the columns for sensation; and farther, that the decussation is only partial with respect to either of these columns; thus elucidating hy the observation of the actual structure what before appeared very unsatisfactory in pathology, and anomalous in disease. The paper is illustrated by drawings made from the dissections of the author.

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.

The Blood Vascular System of Nephtys (Annelida, Polychaeta)

1956 ◽  
Vol s3-97 (38) ◽  
pp. 235-249
Author(s):  
R. B. CLARK
Keyword(s):  
Body Wall ◽  
Vascular System ◽  
Close Association ◽  
Circulatory System ◽  
Ventral Surface ◽  
Blood Stream ◽  
Neurosecretory Cells ◽  
The Body ◽  
Dorsal Vessel ◽  
The Brain

The four longitudinal vessels of the circulatory system of Nephtys californiensis are dorsal, sub-intestinal, and neural, the latter being paired. There is a complete longitudinal circulation; the dorsal vessel communicates with the sub-intestinal by way of the proboscidial circulation and with the neural by way of the circum-oral vessels. In each middle and posterior segment segmental vessels from each of the longitudinal trunks carry blood to and from the parapodia and body-wall. The segmental circulation is completed by a circum-intestinal vessel connecting the dorsal and subintestinal vessels in each segment and an intersegmental branch connecting the dorsal and sub-intestinal segmental vessels. A trans-septal branch of the neural segmental vessel communicates with the sub-intestinal segmental vessel. This arrangement is modified in anterior segments which house the muscular, eversible pharynx, and no blood-vessels cross the coelom except by running through the body-wall. On anatomical grounds and by comparison with other polychaetes it seems likely that segmental is subordinate to longitudinal circulation. There are no endothelial capillaries such as have been described in some other polychaetes; instead there are numerous blindending vessels the walls of which are composed of the same three layers as other vessels and which are probably contractile. The dorsal vessel, where it is in contact with the ventral surface of the supra-oesophageal ganglion, forms a plexus in close association with a modified part of the brain capsule and a special axonal tract within the ganglion. It is thought that by way of this ‘cerebro-vascular complex’, hormones produced in the neurosecretory cells of the brain pass into the blood-stream.

scholarly journals Memoirs: The Development of Symbranchus marmoratus

1913 ◽  
Vol s2-59 (233) ◽  
pp. 1-51
Author(s):  
MONICA TAYLOR
Keyword(s):  
Hepatic Vein ◽  
Alimentary Canal ◽  
Vascular System ◽  
Vena Cava ◽  
The Body ◽  
Pyloric Caeca ◽  
Pectoral Fins ◽  
The Third ◽  
Mature Brain ◽  
The Brain

(A) General Features of Development. (1) The egg of Symbranchus is small, its development typically Teleostean and rapid, the larva hatching out in about seven days at a tropical temperature. (2) A rostrum appears just before the larva hatches, increases in size, attains a maximum length of about 1 mm. when the creature is 7 mm. long, decreases in size, gradually dying down to a rounded pad, and eventually disappears just before tbe adult stage is reached. (3) The larva possesses pectoral fins and the shoulder girdle persists in the adult. These fins appear early, are muscularised by the first three trunk myotomes and innervated by the first three spinal nerves. They develop rapidly, reach their maximum size seven or eight days after hatching, shrivel somewhat, and then drop off bodily at Stage 34. The pectoral fins are mainly respiratory organs and possess a rich network of capillaries. There are three principal blood-streams in the fins--one central, afferent, two marginal, efferent. The establishment of perfect branchial respiration is coincident with the falling off of the fins, i. e. when the creature is ten days old. (4) No trace of pelvic fins has been found. (5) Perforated gill-slits of the Elasmobranch type do not occur in early stages, the clefts only becoming perforate after they are covered by the operculum. When branchial respiration is just beginning the gill-chamber opening is a single crescent-shaped one; as development proceeds the anus of the crescent are gradually obliterated, owing to the fnsion of the backwardly growing operculum with the body-wall, and a single median ventral opening is the result. (6) There is a blind diverticulum in the dorsal roof of the mouth behind the hyoid. (B) Alimentary Canal. (1) The alimentary canal has a typical Teleostean character and development, is solid at first, hollowed out secondarily, and has no obvious connection with the yolk. (2) No air-bladder has been detected at any stage. (3) The pyloric valve arises by outpushings of the intestine. These blind cæcal outgrowths have the appearance of very short rudimentary pyloric cæca. (4) Apart from these structures there are no pyloric cæca. (5) The pancreas is an elongated compact gland arising from a dorsal and two ventral rudiments. (6) The liver is elongated and unilobed. (7) There is a typical thymus arising from clefts 2, 3, 4 and 5. (8) A thyroid arises as a solid median derivative of the floor of the pharynx. It is elongated and bilobed anteriorly. (9) The spleen develops early, is very conspicuous, and multilobed at first. (c) Renal Organs. (1) The pronephric chamber and tubule are formed from the nephrotome of the third trunk myotome. (2) There is no communication at any time between splanchnocœle and nephrocœle of the pronephros. (3) The archinephric duct is formed from the nephrotomes of the segments posterior to the third; the conversion of these nephrotomes into a duct takes place simultaneously, involving no backward growth of the archinephric duct. (4) The pronephros is still present in the oldest larva examined. (5) Mesonephric tubule-rudiments appear in Stage 29. They occur from about Segment 25 to Segment 43. Bach arises as a rounded clump of darkly stained cells in the immediate neighbourhood of the archinephric duct. This rudiment is gradually moulded into a twisted tubule, one end of which becomes converted into a Malpighian capsule of the usual type, the other end acquiring an opening into the archinephric duct. (6) There are no peritoneal funnels. (7) Secondary mesonephric tubules arise in connection with the archinephric duct and with the primary mesonephric tubules. These are not fully differentiated in the oldest larva examined. (8) The anterior much-coiled part of the archinephric duct, as well as the mesonephros, is surrounded by pseudolymphatic tissue. (D) Vascular System. (1) The development of the heart and vascular system agrees generally with that described for other Teleosteans. (2) The free anterior part of the left posterior cardinal disappears, the large right posterior cardinal conveying the blood of the inter-renal vein to the heart. (3) There is a close connection between the blood-vessels of the hinder ends of the kidney and liver recalling the posterior vena cava of Polypterus. (4) The subintestinal vein, the front end of which is the vitelline vein of the earlier stages, persists in the adult as a hepatic vein. This hepatic vein joins up with the left anterior cardinal and left jugular to form the left ductus Cuvieri. The right ductus Ouvieri shows no special peculiarity. (E) Nervous System. (1) The brain is at first solid and is hollowed oat secondarily. (2) Three main divisions of the brain can be distinguished in Stage 21. (3) There is tio cranial flexure until Stage 24, and therefore no reason for assuming that the iufundibulum is the morphologically anterior end of the brain. (4) Sagittal sections through the brain at different stages show the usual Teleostean characters. (5) The cerebellum is late in developing and goes on growing after metamorphosis. (6) The optic lobes of the mature brain are relatively smaller than in the developing one. The mid-brain of the adult is the least conspicuous part. (7) The mature brain is elongate, as also are the olfactory and optio nerves, the divisions well separated off.

EXPERIMENTAL ASSESSMENT OF THE NANOPARTICLES TOXICITY OF NICKEL OXIDE IN TWO SIZES IN THE SUBCHRONIC EXPERIMENT

2018 ◽  
pp. 30-35
Author(s):  
M.P. Sutunkova ◽  
B.A. Katsnelson ◽  
L.I. Privalova ◽  
S.N. Solovjeva ◽  
V.B. Gurvich ◽  
...  
Keyword(s):  
Nickel Oxide ◽  
Nervous Activity ◽  
Equal Mass ◽  
The Body ◽  
Subchronic Toxicity ◽  
Physiological Mechanisms ◽  
Nickel Oxide Nanoparticles ◽  
The Relationship ◽  
The Brain ◽  
Nanoparticles Toxicity

We conducted a comparative assessment of the nickel oxide nanoparticles toxicity (NiO) of two sizes (11 and 25 nm) according to a number of indicators of the body state after repeated intraperitoneal injections of these particles suspensions. At equal mass doses, NiO nanoparticles have been found to cause various manifestations of systemic subchronic toxicity with a particularly pronounced effect on liver, kidney function, the body’s antioxidant system, lipid metabolism, white and red blood, redox metabolism, spleen damage, and some disorders of nervous activity allegedly related to the possibility of nickel penetration into the brain from the blood. The relationship between the diameter and toxicity of particles is ambiguous, which may be due to differences in toxicokinetics, which is controlled by both physiological mechanisms and direct penetration of nanoparticles through biological barriers and, finally, unequal solubility.

Macroscopic Anatomy and Brain Vascularization in the Greater Rhea (Rhea americana americana)

2018 ◽  
Vol 46 (1) ◽  
Author(s):  
Herson Da Silva Costa ◽  
Hélio Norberto De Araújo Júnior ◽  
Ferdinando Vinícius Fernandes Bezerra ◽  
Carlos Eduardo Vale Rebouças ◽  
Danilo José Ayres De Menezes ◽  
...  
Keyword(s):  
Basilar Artery ◽  
Carotid Arteries ◽  
Vascular System ◽  
Cerebral Arteries ◽  
Cervical Region ◽  
Type I ◽  
Macroscopic Anatomy ◽  
Rhea Americana ◽  
Vascular Type ◽  
The Brain

 Background: The Rhea americana americana is a wild bird belonging to the group of Ratites, and is important from the scientific point of view given their adaptability to captivity. Considering that information about its morphology is important for the viability of domesticating the species, the aim of this study was to macroscopically identify the brain regions, as well as the cerebral arteries and the cerebral arterial circuit in order to establish the cerebral vascular pattern and systematization.Materials, Methods & Results: Twenty one brains from young and adult Greater Rheas of both sexes were used from animals that had died due to natural causes and were then kept in a freezer. The specimens were thawed and incised in the cervical region to allow exposure of the left common carotid artery, which was cannulated. The vascular system was rinsed with 0.9% saline solution, then perfused with latex Neoprene 650 stained with red pigment. The animals were subsequently fixed in 3.7% aqueous formaldehyde solution for 72 h, and then they were dissected by removing the bones from the skull cap. The brains were analyzed, and the structures were identified, photographed, schematized and denominated. Morphometric measurements were performed on the basilar and cerebellar ventral caudal arteries, recording the values of length and width in millimeters with the aid of a digital caliper. The brain was divided into: telencephalon, diencephalon, brainstem and cerebellum; while externally, the observed structures are: olfactory bulbs, optical lobes, optic nerves, optic chiasm, pituitary and pineal glands. Vascularization was performed by the following arteries: ventral spinal artery, basilar artery, ventricular cerebellar arteries, medium ventricular cerebellar arteries, caudal branches of the carotid arteries of the brain, ventral mesencephalic artery, cerebral caudal arteries, rostral branches of the carotid arteries of the brain, middle cerebral arteries, cerebroethmoidal arteries, rostral intercerebral anastomosis, rostral cerebral arteries, ethmoidal arteries, internal ophthalmic arteries, inter-hemispheric artery, pituitary arteries, dorsal mesencephalic tectal arteries, dorsal cerebellar arteries, occipital, pineal and dorsal hemispherical branches. The cerebral arterial circuit was both caudally and rostrally closed in 100.0% of the samples, being composed of the arteries: basilar artery, caudal branches of the carotid brain, rostral branches of the brain carotid, cerebroethmoidal arteries and rostral intercerebral anastomosis.Discussion: Encephalon classification regarding the presence or absence of gyri is a characteristic associated to evolution­ary aspects among vertebrates, being respectively considered as lisencephalon or girencecephalus when it presents or does not present convolutions. In Greater Rheas, the telencephalon was quite developed, with a relatively rounded shape and the absence of sulci and convolutions in the cortex, which allowed it to be classified as a lisencephalon. Such findings resemble those described for the ostrich and in a comparative study involving kiwis, emus, owls and pigeons, although different sizes and forms of telencephalon development were observed in the latter. Regarding the cerebral arterial circuit, this structure in Rheas was complete and both caudally and rostrally closed in 100.0% of the specimens. Our findings differ from those ob­served for ostriches, in which a rostrally open behavior has been described, while it is caudally closed in 20.0% of cases and opened in 80.0%. Regarding the vascular type of the brain, in the Rhea it was observed that there was only contribution of the carotid system, similar to that found for birds such as ostriches and turkeys which confer a type I encephalic vascularization.Keywords: arteries, brain, arterial circuit, morphometry, ratites.

The musculature and nervous system of the plerocercoid larva of Dibothriorhynchus grossum (Rud.)

Parasitology ◽  
1941 ◽  
Vol 33 (4) ◽  
pp. 373-389 ◽  
Author(s):  
Gwendolen Rees
Keyword(s):  
Nervous System ◽  
Muscle Mass ◽  
Nerve Cells ◽  
The Body ◽  
Lateral Nerve ◽  
Posterior Median ◽  
The Brain ◽  
Ventral Muscle ◽  
Nerve Cords ◽  
Extrinsic Muscles

1. The structure of the proboscides of the larva of Dibothriorhynchus grossum (Rud.) is described. Each proboscis is provided with four sets of extrinsic muscles, and there is an anterior dorso-ventral muscle mass connected to all four proboscides.2. The musculature of the body and scolex is described.3. The nervous system consists of a brain, two lateral nerve cords, two outer and inner anterior nerves on each side, twenty-five pairs of bothridial nerves to each bothridium, four longitudinal bothridial nerves connecting these latter before their entry into the bothridia, four proboscis nerves arising from the brain, and a series of lateral nerves supplying the lateral regions of the body.4. The so-called ganglia contain no nerve cells, these are present only in the posterior median commissure which is therefore the nerve centre.

scholarly journals The brain dynamics of architectural affordances during transition

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Zakaria Djebbara ◽  
Lars Brorson Fich ◽  
Klaus Gramann
Keyword(s):  
Occipital Cortex ◽  
The Body ◽  
Brain Dynamics ◽  
Alpha Band ◽  
Time Frequency ◽  
Posterior Cingulate ◽  
Sensory Signals ◽  
Event Related Desynchronization ◽  
The Brain ◽  
Attentional Mechanisms

AbstractAction is a medium of collecting sensory information about the environment, which in turn is shaped by architectural affordances. Affordances characterize the fit between the physical structure of the body and capacities for movement and interaction with the environment, thus relying on sensorimotor processes associated with exploring the surroundings. Central to sensorimotor brain dynamics, the attentional mechanisms directing the gating function of sensory signals share neuronal resources with motor-related processes necessary to inferring the external causes of sensory signals. Such a predictive coding approach suggests that sensorimotor dynamics are sensitive to architectural affordances that support or suppress specific kinds of actions for an individual. However, how architectural affordances relate to the attentional mechanisms underlying the gating function for sensory signals remains unknown. Here we demonstrate that event-related desynchronization of alpha-band oscillations in parieto-occipital and medio-temporal regions covary with the architectural affordances. Source-level time–frequency analysis of data recorded in a motor-priming Mobile Brain/Body Imaging experiment revealed strong event-related desynchronization of the alpha band to originate from the posterior cingulate complex, the parahippocampal region as well as the occipital cortex. Our results firstly contribute to the understanding of how the brain resolves architectural affordances relevant to behaviour. Second, our results indicate that the alpha-band originating from the occipital cortex and parahippocampal region covaries with the architectural affordances before participants interact with the environment, whereas during the interaction, the posterior cingulate cortex and motor areas dynamically reflect the affordable behaviour. We conclude that the sensorimotor dynamics reflect behaviour-relevant features in the designed environment.

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