Effect of prolonged restriction of overall motor activity on the hemomicrocirculatory bed of the retina of the rabbit

In 56 rabbits kept in tight cages for 4, 8, 12, 16 and 20 weeks, effect of hypokinesia on structure of hemomicrocirculatory bed of the retina has been studied. The retina is digested in tripsin and then it is exfoliated, and the vessels are stained after Shiff. Diameters of arterioles, capillaries and venules are measured, their relations to each other and number of vessels per square unit are taken into consideration. Restriction of the motor activity for 4 weeks results in narrowing of arterioles, capillaries and venules, in increasing venuloarteriolar coefficient, in decreasing number of vessels per square unit, as compared to the norm. In 8 weeks of hypokinesia the diameter of all links of the hemomicrocirculatory bed is evenly increasing, but it does not reach the normal value; the number of the vessels is keeping to decrease; the venuloarteriolar coefficient is at the same level. In 12, 16 and 20 weeks changes in the diameter and the number of the vessels are poorly pronounced, have a wavy character and diversily directed. The value of the venuloarteriolar coefficient is kept constant. As a whole, the data obtained demonstrate that at a long hypokinesia the animals adapt to the new conditions of existence, and the state of the reticular hemomicrocirculatory bed stabilizes.     

Morphofunctional characteristics of the hemomicrocirculatory bed of the canine pericardium

The hemomicrocirculatory bed in the canine pericardium is presented by arterioles, precapillaries, capillaries, postcapillaries and venules situating in various connective tissue layers of the pericardium. Certain morphological peculiarities of the structure of the hemomicrocirculatory bed links are revealed in various parts of the pericardium. As demonstrate morphometry data, the diameter of all the vessels of the hemomicrocirculatory bed in various parts of the pericardium has no precise differences. There are some fluctuations in the number of the capillaries per 1 mm2 in various parts of the pericardium. Their number is comparatively greater in the area of the vascular porta (transitional fold), in the left lateral, in the ventral and dorsal parts of the pericardium. In these parts of the pericardium the density of the capillaries is increased, the network is especially dense in the area where the pericardial transitional fold passes into the epicardium. In the pericardial microcirculatory blood bed adaptive mechanisms (glomeruli, arteriolo-venular anastomoses, microsphincters) performing regulation of the organ's blood stream, are widely presented.     

Condition of the capillary circulation of gastrointestinal organs after decompression of the portal system by splenorenal anastomosis

The hemomicrocirculatory bed of the gastrointestinal tract organs has been studied in 12 mongrel dogs in 5, 10, 30 days after formation of decompressive splenorenal anastomosis. The most favourable effect the anastomosis renders on hemodynamics in the stomach and duodenal vessels. In these organs during 10 days after the operation phenomena of venous congestion are eliminated, hemorrhages, existed at portal hypertension, resolve, regeneration in the microvessel walls is noted. In the jejunum the restorative processes are slower and complete only 1 month after the operation. The data obtained on the state of the hemomicrocirculatory bed are proved by means of morphometrical investigations.     

Morphologic mechanisms of blood flow regulation in the hemomicrocirculatory system of the human heart during ontogenesis

Hearts of 220 human corpses, who had not any cardiovascular system disease during their life, have been distributed into age groups, beginning from fetuses up to old age. By means of injection, silver nitrate impregnation and scanning electron microscopy methods, applied to corrosive preparations, morphological mechanisms of the blood stream regulation in the hemomicrocirculatory bed of the human heart have been revealed in ontogenesis. The first group of the regulation mechanisms includes proper mechanisms inherent in the links of the microbed: spatial orientation of microvessels, precapillary sphincters, anastomoses between these vessels, sequence in arrangement of the endothelial cell nuclei, length, diameter and number of links in the microcirculatory bed. The second group embraces those mechanisms, that depend on structure of the myocardial wall, influencing the microcirculatory bed.     

Relation between neural structures possessing acetylcholinesterase activity and the hemomicrocirculatory bed of the fascia of the rat

By means of Karnovsky--Roots method the nervous apparatus of the hemomicrocirculatory bed has been revealed in the subcutaneous muscle fascia possessing acetylcholinesterase (AChE) activity. Innervational peculiarities in some microvascular branches, bushy pattern of AChE-positive nervous structures have been stated, as well as their uneven distribution along the vessels.     

The hemomicrocirculatory bed in the wall of hollow organs of the gastrointestinal tract of dogs with portal hypertension

At portal hypertension, produced by means of experimental stenosis of the portal vein in the hemomicrocirculatory bed of hollow organs of the gastrointestinal tract, congestive phenomena and edema of walls in the organs are observed. Manifested dilatation is noted in the lumen of arterioles, venules, postcapillary venules and capillaries. At early stages after the operation average diameters of these vessels in the submucosal base of the small intestine become increased 3-7 times and they do not return to the initial size even at late stages. The precapillary sphincters are in the state of spasm. Overdistention of walls in microvessels of the venular part of the functional module results in their increased permeability, that is demonstrated as diapedesic hemorrhages. During formation of intraorganic and extraorganic peripheral pathways of the circulation, the congestive phenomena in the hemomicrocirculatory bed disappear gradually.     

Hemomicrocirculatory bed in the rabbit small intestine wall during ontogenesis

Hemomicrocirculatory bed has been studied in fragments of the small intestine wall, obtained from 30 rabbits of various age. During ontogenesis the number and caliber of all components of the hemomicrocirculatory bed increase, as well as density of the capillary network in connection with formation and growth of the small intestine membranes. At the age of two or three years involutive changes are observed in the blood bed of this organ.     

Organizational features and morphometric characteristics of the hemomicrocirculatory bed of the human brain dura mater

By means of silver nitrate impregnation and hematoxylin -- eosin staining the microcirculatory bed of the human brain dura mater (the second half of the mature age) has been investigated. Owing to the analysis of the morphometrical data of module organization of the hemomicrocirculatory bed, an objective quantitative characteristics of its peculiarities in various layers and areas of the dura mater is presented. In three layers of the dura mater in the fornix and skull basis area, falx cerebri and tentorium cerebelli venular links predominate. Most of all morphometrical parameters of the venular vessels increase in the internal layer of the dura mater in the skull basis area. Conditions of functioning for the human brain dura mater are reflected in its blood bed, its specificity manifesting at the microcirculatory level.     

Microcirculatory bed of the human duodenum

In preparations impregnated with silver nitrate (25 corpses of mature persons), the hemomicrocirculatory bed of the intestine wall tunics has been stated to possess a layer-by-layer organization. The most powerful submucosal vascular plexus, formed by branches of the arteries perforating the external tunics of the intestine, supplies with blood all the layers of the intestinal wall and their main working and integrating elements: intestinal and duodenal glands, villi, neural ganglia and trunks of the submucosal and intermuscular plexuses. Summarizing morphometrical criteria for estimating the capillary bed of the tunics of all the anatomical parts and the large duodenal papilla, it is clear that there are specific conditions in microvascularization of the upper part of the organ.     

Structural features of the intrinsic venous bed of the human urinary bladder

The intraorganic veins of the human urinary bladder have been studied in a vast sectional material. The veins within the organ make an enormous multilayered plexus which is differently organized in various layers of its wall. Abundant anastomoses, multiplicated ways for outflow from every layer, manifested interactions between the venous plexuses are specific for the intraorganic venous bed of the urinary bladder. The structures for an active regulating the hemomicrocirculatory blood stream are widely presented in the urinary bladder. In its every tunic certain specific morpho-functional features for organization and adaptation of the intraorganic venous bed are revealed.     

Patterns in the development of the ultrastructure of elements of the microcirculatory system in the early stages of human embryogenesis

By means of transmissive electron microscopy methods, general regularities in development of the microcirculatory system have been studied at early stages of the human prenatal ontogenesis in functionally different organs. Ultrastructure of two cell types has been described in the mesenchyme of human embryos. Formation mechanisms of the primary blood vessels belonging to the protocapillary type are revealed. Structural peculiarities of the primary protocapillary network differentiating into various links of the secondary organospecific hemomicrocirculatory bed are distinguished. Certain stageness in development of the microcirculatory system is stated, its blood circulatory compartment including. Two stages are determined in development of the microcirculatory system: prevascular and vascular microcirculation. The latter includes the precirculatory and circulatory phases.     

Condition of the microcirculatory bed of the bulbar conjunctiva in physiological and pathological pregnancies

By means of biomicroscopic method the bulbar conjunctiva in 150 women (18-35 years of age) have been examined. Of them: 30 healthy women make the control group; the second group includes 60 healthy women at their first and second half of pregnancy; the third group includes 60 women with pregnancy developing against the background of noncomplicated insulin-dependent diabetus mellitus during their first and second half of pregnancy. In the healthy women there are not any significant changes in most of the parameters of the microcirculatory bed during the first half of their pregnancy, and in the second half of their pregnancy a great density of the blood vascular bed is determined. Diameters of all vessels in the hemomicrocirculatory bed are significantly increased, as compared to those in the control group. In the women suffering from diabetus mellitus, during the first half of pregnancy certain changes in the picture of the vascular network is observed, as well as an increased convolution. uneveness in distribution of blood vessels; in the second half of their pregnancy a pronounced deformity of the vacular network is observed, decreasing diameter of afferent vessels and an essential dilatation of postcapillaries and venules are registered. Certain signs of aggregation of blood formed elements is noted.     

Development of the hemomicrocirculatory bed of the human gonads during the prenatal period of ontogeny

The formation of the organospecific hemomicrocirculatory bed of the ovaries and testes has been studied by a complex of light, transmissive and scanning electron microscopy in 3--9-month-old human fetuses. The change of the diffusive protocapillary bed is secured by: 1) reduction of some protocapillaries; 2) appearance of secondary capillaries from the growth buds of the preceeding microvessels; 3) formation of arteriolar and venular links of the hemomicrocirculatory bed from the protocapillaries at the expense of differentiation of the developing paravasal connective tissue into cellular elements of the muscular and adventitial tunics. The secondary blood capillaries of the human gonads are predominantly formed intraendothelially. During the prenatal ontogenesis presence of the secondary blood capillaries of somatic uninterrupted type is specific for the human gonads.     

Hemomicrocirculatory bed of the muscles of the shoulder and forearm

By means of classical anatomical techniques: injection of contrast masses into the vascular network, macro-microscopic preparation, translucency, roentgenography, and some histological techniques, peculiarities of the hemomicrocirculatory bed in muscles of the human arm and forearm have been revealed. Small arteries of the 3d-4th order run along the muscle fiber fasciculi. In the center of the 2d order muscle fasciculus, in its internal perimysium, arteriole and venule (or 2 venules) run; from them into the 1st order fasciculus, precapillary arterioles and postcapillary venules, connected by means of capillaries, run. The arteriole and the venule, accompanying it, together with the precapillary arterioles and postcapillary venules, branching off them, form a unit of the microcirculatory bed of the arm and forearm muscles (module). Well developed intramuscular arterial anastomoses, presence of isolated structural-functional units of the hemomicrocirculatory bed ensure functional prosperity of the human muscles.     

Vascular anastomoses of the blood microcirculatory bed of the human heart

Using a complex of morphological techniques both injective and non-injective, scanning electron microscopy including, the hemomicrocirculatory bed and vascular anastomoses have been studied in various parts of the human heart. In most cases anastomoses between the microcirculatory links are realized at the level of capillaries, precapillary arterioles and postcapillary venules. Venulo-venular anastomoses are demonstrated in the myocardium. Existence of terminal arterioles is discussed.     

Histo-functional interrelations of the atrial hemomicrocirculatory bed in ontogenesis

In 110 hearts of corpses of fetuses beginning from 7 months of age and those of persons up to the age of 86 years, using various histological techniques, as well as in 20 canine hearts, using certain histochemical techniques, interrelations of the hemomicrocirculatory bed, myocardiocytes, elements of the connective tissue have been studied. Application of correlative and analysis of variance makes it possible to reveal direction and significance of the connections between the structural components of the atrial walls, as well as influence of age on the parameters investigated. The interrelations and interconnections between separate components of the atrial structural organization are complex, they change in the process of individual development, reflect development of the atrial wall and the heart as a whole.     

Changes in the circulatory bed of the muscles of the hindlimb after their transplantation to the perineum and the formation of the anal sphincter

After investigations performed concerning the hemomicrocirculatory bed of the m. gracilis, m. rectus femoris, m. adductor longus and m. semitendinosus in 100 dogs transplanted on the perineum in order to form the rectal closing apparatus, according the technique elaborated, it has been stated that reaction of the blood bed of the muscle flaps in all experimental series is identical. During the restorative process of the disturbed hemocirculation in the muscle flap and in the intestinal closing apparatus built, certain phasesness in development of adaptive reactions is observed, that corresponds to the known syndrome "economization" microcirculation.     

Ultrastructural regularities of new growth of secondary micro blood vessels in the prenatal period of human morphogenesis

By means of transmissive electron microscopy structural aspects of new formation of secondary blood microvessels in functionally different organs have been studied during fetal period of the human development. Growth buds appear on the basal surface of the endothelial lining of the blood microvessels predominantly in those areas of the vascular wall, where pericytes and adventitial cells are absent. The first stage in formation of the growth bud is separating of small compartments in the lumen of the maternal vessel. Then, connected by means of specialized contacts, endothelial cells of such a compartment move one by one towards periphery of the vessel and form the growth bud, protruding outside. In the area of the growth bud local destruction of the basal membrane is observed. Newly formed microvessels, anastomising, form vascular loops. Further processes in differentiation of separate segments of the newly formed capillary network into links of the hemomicrocirculatory bed are analogous to those, observed in the course of differentiation of the primary protocapillary network into the secondary intraorganic blood bed.     

Organ and tissue-specific properties of the microcirculatory bed of the heart

The auricular and ventricular microcirculatory bed has been studied in persons of mature age, not suffering from any cardio-vascular diseases during their life. As a whole, 48 objects have been studied. The microcirculatory bed has been revealed in sections of the cardiac wall 70-100 mcm thick using silver nitrate impregnation after V. V. Kuprianov. Organ- and tissue-specific properties of the vascular microcirculatory bed are revealed in interrelations of the vessels and the structural elements of the cardiac wall (myocardium, and connective tissue structures), in position of nuclei of the endothelial cells of the capillary wall and in places of the capillary branchings. Principle differences in structure of the auricular and ventricular microcirculatory bed are demonstrated. The notion the organ- and tissue-specific properties of the microcirculatory bed vessels is discussed.     

Development of the paravascular bed of the vessels of the human heart during the prenatal period of ontogenesis

The paravascular bed of the cardiac vessels has been studied in 128 human fetuses at the age of 3-9 lunar months. Anatomical and histological techniques have been used, morphometrical analysis has been carried out. The paravascular bed of the cardiac wall vessels begins to form from the vascular epicardial network and from the paraneural vessels in 5-month-old fetuses. The paravasal longitudinal tracts are the first to form (the venous ones preceed the arterial). During the seventh month the nutritive vessels and the intramural networks of the main cardiac arteries and veins develop. The formation of the paraarterial bed is connected with the vascular diameter and with thickness of the arterial walls. Certain regularities in development of the venous paravascular bed are defined. By the beginning of the 8th month there are all main components of the paravascular bed of the cardiac vessels.