The Fate of Thorium Dioxide Injected into the Pedal Sinus of Bullia (Gastropoda: Prosobranchiata)

1965 ◽  
Vol 42 (3) ◽  
pp. 509-519
Author(s):  
A. C. BROWN ◽  
ROSALIND J. BROWN

1. The removal and ultimate disposal of foreign particles injected into the haemolymph of the sandy-beach snail, Bullia, has been studied by using the radio-opaque dye Thorotrast. 2. Particles are removed by phagocytic haemocytes which migrate by various routes to the outside of the body. The main pathway is through the heart wall into the pericardial cavity and via the renopericardial canal into the lumen of the kidney, from which the cells escape into the mantle cavity. 3. The injection of foreign particles stimulates a marked increase in the haemocyte population and also in the mitotic index. 4. The final discussion integrates the available evidence and a comparison is made between Bullia and other molluscs. The origin of the macrophages is discussed.

1973 ◽  
Vol 59 (2) ◽  
pp. 291-303
Author(s):  
BARBARA A. SOMMERVILLE

1. The pressure changes in the mantle cavity and various parts of the circulatory system of Helix pomatia have been measured. 2. There are characteristic pressure changes associated with the breathing movements, the pattern depending upon the point at which the measurement was made and, in the case of the heart, the position of the body at the time of recording. These pressure changes fail mainly within the range 2-8 cm H2O. 3. The pressure changes associated with contraction of the heart chambers fall within the range 1-2 cm H2O in pulmonary vein and auricle, 10-32 cm H2O in the ventricle, 1-3 cm H2O in the aorta and 1-8 cm H2O in the pericardial cavity. 4. An increased frequency and amplitude of heart beat was associated with an increased rate of blood flow.


1992 ◽  
Vol 66 (2) ◽  
pp. 96-99 ◽  
Author(s):  
M. E. Adam ◽  
J. W. Lewis

ABSTRACTExperimental infection of Echinoparyphium recurvatum von Linstow (Digenea: Echinostomatidae) cercariae in the snail second intermediate host Lymnaea peregra Müller shows that metacercarial encystment takes place on the lining of the mantle cavity, pericardial cavity and kidney lumen, with the mantle cavity the most preferred site. All three sites are accessible via the body openings. The metacercariae appear to be more susceptible to encapsulation in the visceral mass than in the cavity of the mantle, pericardium and the lumen of the kidney.


1973 ◽  
Vol 59 (2) ◽  
pp. 275-282
Author(s):  
BARBARA A. SOMMERVILLE

1. Helix uses the muscular floor of the mantle cavity to effect several movements. The contraction and relaxation of these muscles is concerned primarily with filling the lung and absorption of oxygen under pressure. The movement is linked with that of the pneumostome, which is open while the floor is depressed and closed when it is raised. An exaggeration of the breathing movements serves to generate the pressure in the cephalopedal haemocoel, which propels the anterior part of the body out of the shell. 2. The rate and regularity of heart-beat vary during the breathing cycle, being slow and irregular when the pneumostome is closed and fast and regular when it is open. 3. Observation of the intact heart of Helix showed changes in the degree of filling indicating an increased blood flow from the haemocoel to the pulmonary veins and heart when the mantle cavity floor was depressed. The total volume of the heart and pericardial cavity was greater at ventricular diastole than at ventricular systole. 4. When the cardiac nerve was severed a significant but inconsistent relationship between the heart activity and the breathing cycle remained. 5. Helix pomatia, H. aspersa, Archachatina, Monodonta and Anion ater all have a semilunar valve on the common aorta directed so as to prevent blood flowing from the aorta into the ventricle. H. pomatia and H. aspersa have a second semilunar valve in the anterior aorta while in Archachatina the anterior aorta passes through a muscular constriction.


2017 ◽  
Vol 9 ◽  
pp. 117906521772090 ◽  
Author(s):  
Noppon Taksaudom ◽  
Metus Ketwong ◽  
Nirush Lertprasertsuke ◽  
Aphisek Kongkaew

Objective: The operating procedure of a resternotomy in open-heart surgery is a complicated procedure with potentially problematic outcomes partly due to potential adhesions in the pericardial cavity and retrosternal space. Use of a collagen membrane has shown encouraging results in adhesion prevention in several regions of the body. This study was designed to evaluate the effectiveness of the use of this collagen membrane in the prevention of pericardial adhesions. Materials and methods: A total of 12 pigs were divided randomly into 2 groups: an experimental group in which collagen membranes were used and a control group. After sternotomy and an anterior pericardiectomy, the epicardial surface was exposed to room air and irrigated with saline, and an epicardial abrasion was performed using a sponge. The pericardial defect was repaired using a collagen membrane in the experimental group or left uncovered in the control group. After 8 to 12 weeks, the pigs were killed, and a resternotomy was performed by a single-blinded surgeon enabling the evaluation of adhesions. The heart was then removed and sent for microscopic assessment conducted by a single-blinded pathologist. Results: The resternotomy operations performed using a collagen membrane demonstrated a nonstatistically significant trend of fewer macroscopic and microscopic adhesions in all regions ( P > .05), particularly in the retrosternal and defect regions. Conclusions: This study showed nonstatistically significant differences between the outcomes in the collagen membrane group and the control group in both macroscopic and microscopic adhesion prevention. Due to the many limitations in animal study design, further studies in human models will be needed before the true value of this procedure can be evaluated.


2013 ◽  
Vol 50 (4) ◽  
pp. 244-250 ◽  
Author(s):  
Gustavo Lemos PELANDRÉ ◽  
Maria Célia DJAHJAH ◽  
Emerson Leandro GASPARETTO ◽  
Marcelo Souto NACIF ◽  
Edson MARCHIORI ◽  
...  

ContextGastrointestinal stromal tumors are uncommon abdominal neoplasms and can affect any portion of the gastrointestinal tract.ObjectivesDescribe the tomographic findings of the gastrointestinal stromal tumor of gastric origin, correlating it with the mitotic index.MethodsTwenty-one patients were selected within the period of January 2000 and 2008, with histopathological and immunohistochemical diagnosis of gastric gastrointestinal stromal tumors, who presented computed tomography done before the treatment. The tomographic variables analyzed were lesion topography, dimensions, contours, morphology, pattern and intensity enhancement through venous contrast, growth pattern, invasion of adjacent organs, presence of ulceration, fistula, calcifications, infiltration of mesenteric fat, lymphadenopathy and metastasis. The mitotic index was determined through optic microscopy, counting the number of mitosis figures in 50 high power fields.ResultsThe tumors were located in the body (66.7%) or gastric fundus (33.3%), with dimensions varying between 4.2 and 21.2 cm (average of 10.5 cm). The growth was predominantly extraluminal (47.6%) or intra/extra luminal (28.6%). The enhancement by venous contrast was heterogeneous in 66.7%. The statistical analysis showed that irregular morphology (P = 0.027) and infiltration of mesenteric fat (P = 0.012) presented correlation with the high mitotic index.ConclusionsIn the present study, most part of the tumors were located in the gastric body, with average size of 10.5 cm, presenting central hypo dense area, heterogeneous enhancement through contrast and predominantly extra luminal growth. Irregular morphology and infiltration of mesenteric fat present statistical correlation with high mitotic level.


2021 ◽  
Vol 23 (103) ◽  
pp. 145-151
Author(s):  
L. P. Goralskyi ◽  
M. R. Ragulya ◽  
I. M. Sokulskyi ◽  
N. L. Kolesnik ◽  
I. Y. Goralska

The paper presents the results of macro- and microscopic structure of cattle heart on the organ-, tissue- and cell levels. The samples of the selected material (n = 5) were preserved in a 10–12 % water solution of neutral formaline with its further charging into wax. Histologic sections not more than 10 mkm were made from wax blocks by using a sliding microtome MC-2. Hematoxilin- and eosin staining of histological sections by Heydengine technique was used for studying cell morphology, carrying out morphometrical studies and for receiving review samples. Histoarchitecture of the structural parts of the heart (ventricle and auricle) and their morphometrical parameters were studied on the histological preparations using the light microscopy technique. The experimantal part of the scientific research was carried out in compliance with the requirements of “European Convention for the Protection of Vertebrate Animals used for Experimantal and other Scientific Purposes” (Strussburg, 1986). The cattle heart is located in a thorax between two lungs, in front of a diaphragm and shifted left. In the 3rd–4th rib region the heart adjacents to a thoracic wall. The heart apex is in the 5th rib region. The absolute weight of a cattle heart equals 2143.27 ± 38.76 g, the relative weight equals – 0.43 ± 0.006 %. The net weight of the heart without the epicardial fat equals 1926.12 ± 31.12 g. Herewith, the weight of the aortic ventricle equals 978.54 ± 19.52 g, the weight of the pulmonic ventricle equals 554.17 ± 14.21 g, the weight of both ventricles equals 1539.08 ± 49.74 g. The auricles weight was the least and equaled 397.18 ± 11.21 g. The ratio of the ventricle weight of the heart to its net weight equals 1:0.2, and the ratio of the weight of the auricle myocard to the weight of the ventricle myocard equals 1:0.26. The heart height equaled 23.08 ± 0.11 сm, width – 13.9 ± 0.18 cm and the circumference – 38.08 ± 0.9 cm. According to the analysis of such liniar measurements, the cattle heart in the animals of the experimental group is characterized as that of an enlarged- and short form. The heart wall consists of three sacs – endocardium, myocard and epicardium. The dominating weight of the heart wall is in a muscular layer (myocard), which consists of transversus stripe muscular fibers which are formed on the basis of mononuclear cells – cardiomyocytes which are interlinked into muscular fibers. According to the cytometric analysis of cardiomyocytes, their largest volume – (11225.73 ± 824.42 mkm3) is observed in the aortic ventricle, smaller – (7963.60 ± 627.09 mkm3) – in a pulmonic ventricle and the smallest – (5361.60 ± 583.91 mkm3) in the auricle cardiomyocytes. Herewith, the volumes of cardiomyocytes nuclei in an aortic ventricle (124.55 ± 7.99 mkm3 and in a pulmonuc ventricle (121.67 ± 7.02 mkm3) are nearly the same, and in the auricle cardiomyocytes the nuclei volume is significantly smaller and it equals 101.05 ± 6.04 mkm3 respectively. Such morphometrical parameters of cardiomyocytes and their nuclei are evidenced in their nuclei-cytoplasmatic ratio, which is the smallest in the cardiomyocytes of an aortic ventricle – 0.0113 ± 0.0068, somewhat larger in a pulmonic ventricle – 0.0156 ± 0.0054 and the largest – 0.0234± 0.0058 in the auricle cardiomyocytes, that is connected with the special properties of the muscular tissue of a myocard which is capable of spontaneous rythmic beatings depending on their morphofunctional load: the ventricles pump the blood from the heart to the body performing the gratest load (the aortic ventricle acts a s a pump, and the pulmonic ventricle acts as a container), the auricles receive the blood which returns to the heart from the animal body, performing somewhat smaller load.


SLEEP ◽  
2019 ◽  
Vol 42 (5) ◽  
Author(s):  
Daniela Grimaldi ◽  
Nelly A Papalambros ◽  
Kathryn J Reid ◽  
Sabra M Abbott ◽  
Roneil G Malkani ◽  
...  

Abstract Slow-wave sleep (SWS) is important for overall health since it affects many physiological processes including cardio-metabolic function. Sleep and autonomic nervous system (ANS) activity are closely coupled at anatomical and physiological levels. Sleep-related changes in autonomic function are likely the main pathway through which SWS affects many systems within the body. There are characteristic changes in ANS activity across sleep stages. Notably, in non-rapid eye-movement sleep, the progression into SWS is characterized by increased parasympathetic activity, an important measure of cardiovascular health. Experimental manipulations that enhance slow-wave activity (SWA, 0.5–4 Hz) can improve sleep-mediated memory and immune function. However, effects of SWA enhancement on autonomic regulation have not been investigated. Here, we employed an adaptive algorithm to deliver 50 ms sounds phase-locked to slow-waves, with regular pauses in stimulation (~5 s ON/~5 s OFF), in healthy young adults. We sought to determine whether acoustic enhancement of SWA altered parasympathetic activity during SWS assessed with heart rate variability (HRV), and evening-to-morning changes in HRV, plasma cortisol, and blood pressure. Stimulation, compared with a sham condition, increased SWA during ON versus OFF intervals. This ON/OFF SWA enhancement was associated with a reduction in evening-to-morning change of cortisol levels and indices of sympathetic activity. Furthermore, the enhancement of SWA in ON intervals during sleep cycles 2–3 was accompanied by an increase in parasympathetic activity (high-frequency, HRV). Together these findings suggest that acoustic enhancement of SWA has a positive effect on autonomic function in sleep. Approaches to strengthen brain–heart interaction during sleep could have important implications for cardiovascular health.


Author(s):  
R. C. Newell ◽  
H. R. Northcroft

The rate of cirral beat of Balanus balanoides is related to the logarithm of the body weight as an exponential function. In any one animal, there is little effect of temperature on cirral activity between 7·5° and 10° C. Between 10° and 20° C, however, there is a rapid increase in cirral beat with temperature followed by a fall at temperatures above 20° C.Balanus balanoides exhibits a fast, medium and zero rate of oxygen consumption. These rates of oxygen consumption correspond with (a) normal cirral beating, (b) ‘testing’ activity with no cirral movement, and (c) with the closure of the mantle cavity. Both of the possible levels of oxygen uptake are related to the logarithm of the body weight in a logarithmic fashion over the temperature range 7·5°–22·5° C. Temperature affects the two rates of oxygen consumption differently. In the slower rate (rate B) there is an increase in the rate of oxygen consumption between 7·5° and 14° C but there is no significant increase in the rate of oxygen consumption between 14° and 22·5 C°.


1962 ◽  
Vol 68 (3) ◽  
pp. 237-260
Author(s):  
Krishna Chandra Ghose

SynopsisOrganogenesis is completed by 15 days. A modified veliger stage is present. Torsion begins at about the sixth day. The foot rudiment is first to appear. The stomodæum appears as a new structure. The salivary glands develop from the stomodæum by evaginations. The œsophagus is stomodæal, while the crop and the primitive stomach are archenteric in origin. The digestive gland develops as two outgrowths of the primitive stomach. The hind gut is formed by the cells proliferated from the closed posterior end of the archenteron. It opens into the primitive stomach in a 2·5 mm. embryo, and the anus appears very late. The proctodæum is absent. The primordium of the pericardium with the heart, definitive kidney and gonad is mesodermal. The ureter is ectodermal and arises from the mantle cavity by evagination and subsequently communicates with the kidney. Lung and mantle are ectodermal and arise by separate invaginations. The lung fuses with the mantle and loses its separate existence from about a 4 mm. embryo. The nervous system is early to appear and the sense organs, except the statocysts are late in origin. They are ectodermal. The larval organs are: velum, podocyst, larval kidney, nuchal cells and larval digestive gland. The prototroch is the rudiment of the velum. It appears in a very early embryo from the posteroventral part and marks off the anterior border of the stomodæum. The cells of the prototroch become hyaline, vacuolate and develop cilia in a 2·25 mm. embryo, and it is transformed into velum. The velum helps in driving albumen into the larval and adult digestive glands and is resorbed in the body-wall epithelium. The rudiment of the foot first appears after the completion of gastrulation, and the podocyst is differentiated from it later. It steadily increases in size, assumes a hood-like shape, exhibits contraction and relaxation movements and begins to reduce when the embryo attains 3·25 mm. size. It is completely resorbed in the foot. The larval kidneys are mesodermal in origin, appear, in a 920 μ embryo. They begin to degenerate after the formation of the functional definitive kidney and disappear in a late larva. The kidneys are U-shaped, the cells of the closed anterior and bear pseudopodia, which are almost totally replaced by cilia afterwards. The kidney opens to the exterior posteriorly. The cells become vacuolated and excretory granules accumulate in the vacuoles. The nuchal cells first appear in a 2·5 mm. embryo and are excretory. They increase both in number and size with the growth of the embryo and persist throughout the larval period. The endoderm cells of the major portion of the archenteron except a small posterior part, enlarge in size, develop vacuoles and form a larval digestive organ for the purpose of digestion of albumen. Even after the formation of the adult digestive gland, the larval digestive gland functions for a short time, then degenerates and disappears at the end of the larval life.


Paleobiology ◽  
1977 ◽  
Vol 3 (2) ◽  
pp. 196-206 ◽  
Author(s):  
Robert M. Linsley

Five generalizations derived from the shell form of prosobranch gastropods are developed. (1) A univalve of more than one volution whose aperture lies in a plane that passes through the axis of coiling does not live with the aperture parallel to the substrate. (2) A univalve of more than one volution whose aperture lies in a plane that is tangential to the body whorl does live with the plane of the aperture parallel to the substrate. (3) Gastropods with tangential apertures, when extended, support the shell so that the center of mass of the shell and its contents is over the midline of the cephalopedal mass; this balancing of the shell may be accomplished either by regulatory detorsion, by inclination or by a combination thereof, to keep the center of gravity of the shell as low as possible. (4) Angulations or re-entrants in the gastropod aperture are usually indicative of inhalent or exhalent areas; inhalent areas are directed as far anteriorly as possible. (5) Gastropods having elongated apertures possess only a single gill and develop a water current through the mantle cavity from anterior to posterior along the long axis of the aperture; this axis is subparallel to the anterior-posterior axis of the foot.These generalizations are then used as the basis for some deductive interpretations of behavioral modes of Paleozoic Gastropoda.


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