scholarly journals The postural system as a functional venous pump

Author(s):  
Vladimir Usachev ◽  
Pierre-Marie Gagey

Background: In the 90s, Inamura et al. have drawn our attention to the role played by the postural system in the return venous circulation, thanks to plethysmographic recordings which gave free rein to the imagination of the authors to suppose the functioning mechanisms of this venous pump. In 2010, two anatomists, Uhl & Gillot, transformed our representation of the venous network and made assumptions about the functioning of the venous pump. Objective/ Methods: The aim of this work is to verify these hypotheses by scanning the venous blood flow at the level of the sinus soleus and the popliteal vein during various posture-kinetic situations. Conclusion: These studies fully confirm the hypotheses. It is therefore likely that the postural system intervenes not only in the phenomena of stabilisation of the body, but also in the back venous circulation.

2017 ◽  
Vol 16 (3) ◽  
pp. 214-219 ◽  
Author(s):  
Marta Gimunová ◽  
Martin Zvonař ◽  
Kateřina Kolářová ◽  
Zdeněk Janík ◽  
Ondřej Mikeska ◽  
...  

Abstract Background During pregnancy, a number of changes affecting venous blood flow occur in the circulatory system, such as reduced vein wall tension or increased exposure to collagen fibers. These factors may cause blood stagnation, swelling of the legs, or endothelial damage and consequently lead to development of venous disease. Objectives The aim of this study is to evaluate the effect of special footwear designed to improve blood circulation in the feet on venous blood flow changes observed during advancing phases of pregnancy. Methods Thirty healthy pregnant women participated in this study at 25, 30, and 35 weeks of gestation. Participants were allocated at random to an experimental group (n = 15) which was provided with the special footwear, or a control group (n = 15). At each data collection session, Doppler measurements of peak systolic blood flow velocity and cross-sectional area of the right popliteal vein were performed using a MySonoU6 ultrasound machine with a linear transducer (Samsung Medison). The differences were compared using Cohen’s d test to calculate effect size. Results With advancing phases of pregnancy, peak systolic velocity in the popliteal vein decreased significantly in the control group, whereas it increased significantly in the experimental group. No significant change in cross-sectional area was observed in any of the groups. Conclusions Findings in the experimental group demonstrated that wearing the footwear tested may prevent venous blood velocity from reducing during advanced phases of pregnancy. Nevertheless, there is a need for further investigation of the beneficial effect on venous flow of the footwear tested and its application.


Author(s):  
Abinand Manorama ◽  
Tamara Reid Bush

Pressure ulcers have been a concern in healthcare settings, with more than 50% of bedridden or wheelchair-bound patients being affected [1]. Pressure ulcers typically occur on a region of the body that experiences forces from an external structure (e.g. bed, wheelchair). Researchers believe that such forces cause a decrease in blood flow, which results in tissue necrosis, causing pressure ulcers [2].


2015 ◽  
Vol 39 (4) ◽  
pp. 405-410 ◽  
Author(s):  
Caroline Altermann ◽  
Rithiele Gonçalves ◽  
Marcus Vinícius S. Lara ◽  
Ben-Hur S. Neves ◽  
Pâmela B. Mello-Carpes

The purpose of the present article is to describe three simple practical experiments that aim to observe and discuss the anatomic and physiological functions and differences between arteries and veins as well as the alterations observed in skin blood flow in different situations. For this activity, students were divided in small groups. In each group, a volunteer is recruited for each experiment. The experiments only require a sphygmomanometer, rubber bands, and a clock and allow students to develop a hypothesis to explain the different responses to the interruption of arterial and venous blood flow. At the end, students prepare a short report, and the results are discussed. This activity allows students to perceive the presence of physiology in their daily lives and helps them to understand the concepts related to the cardiovascular system and hemodynamics.


2004 ◽  
Vol 20 (2) ◽  
pp. 115-128 ◽  
Author(s):  
Jean-Thomas Aubert ◽  
Christian Ribreau

Blood flows toward the heart through collapsible vessels, the veins. The equations of flow in collapsible tubes in motion show a strong dependence on body forces resulting from gravity and acceleration. This paper analyzes the contribution of body forces to venous blood flow during walking on level ground. It combines the biomechanics of gait and theory of collapsible tubes to point out that body forces due to gravity and limb acceleration cannot be overlooked when considering the determinants of venous blood flow during locomotion. The study involved the development of a kinematic model of the limb as a multi-pendulum arrangement in which the limb segments undergo angular displacements. Angular velocities and accelerations were determined and the body forces were calculated during various phases of the gait cycle. A vascular model of the leg's major venous system was also constructed, and the accelerations due to body and gravity forces were calculated in specific venous segments, using the data from the kinematic model. The results showed there were large, fast variations in the axial component (Gx–Mx) of the body forces in veins between the hip and the ankle. Acceleration peaks down to –2G were obtained at normal locomotion. At fast locomotion, a distal vein in the shank displayed values of (Gx–Mx)/G equal to –3.2. Given the down-to-up orientation of the x-axis, the axial component Mx was usually positive in the axial veins, and Mx could shift from positive to negative during the gait cycle in the popliteal vein and the dorsal venous arch.


2021 ◽  
Vol 17 (1) ◽  
pp. 42-49
Author(s):  
O.Ye. Kovalenko ◽  
N.G. Prityko

The article presents an analytical review of the results of domestic and foreign studies on chronic disorders of cerebral venous circulation, which is given less attention against the arterial system due to blurred manifestations, especially early, anatomical variability of the venous system, even in healthy, difficulty in diagnosis. When the balance of arterial and venous inflow is disturbed and this state exa­cerbates, irreversible changes evolve other structures of the cranial ca­vity — primarily in the brain (consistent with the concept of Monroe-Kelly). Chronic disorders of cerebral venous circulation may have different causes and varying degrees of severity. The equivalent of chronic cerebral venous insufficiency (SCVD), terminologically accepted in our country, in some countries is considered as chronic venous cerebrospinal insufficiency, which emphasizes the pathogenetic link of disorders of cerebral venous blood flow and extracranial veins, which is, in our opinion, is logical and reasonable. Recognition of chronic cerebrospinal venous insufficiency has aroused intense interest for a better understanding of the role of extracranial venous pathology and developmental options. Although the diagnosis was originally based on Doppler sonography, there are currently no diagnostic imaging methods, non-invasive or invasive, that can serve as the gold standard for detecting venous abnormalities indicative of chronic cerebrospinal venous insufficiency. The results of some studies are discussed, in particular, the hypothesis that chronic cerebrospinal venous insufficiency plays a role in the pathoge-nesis of multiple sclerosis or in many concomitant clinical manifestations. The affinity of the pathogenesis of idiopathic intracranial hypertension, Ménière’s disease, spondylotic vertebrobasilar insufficiency syndrome is analyzed. Attention is also focused on the other opinion of scientists when the increase in venous blood supply to the brain and other formations in the head cavity under certain conditions is considered as a compensatory reaction. The anatomical and physiological features of the venous system of the cranial cavity are considered, which substantiate the clinical manifestations of venous dysfunction, methods of diagnosis and treatment of pathology. Summarizing the above, chronic venous blood circulation in the cranial cavity, which is largely associated with problems of extracranial venous blood flow, not only in itself is a very characteristic syndrome complex t that adversely affects neurological functions due to cerebral hypoxia and metabolic changes, deteriorates the quality of life, but also has a negative impact on the course of the disease or has a pathogenetic link with other diseases, in particular, may be accompanied by different levels of blood pressure.


2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Thomas Charles ◽  
Stephen Mackintosh ◽  
James Fingleton ◽  
Irene Braithwaite ◽  
Mark Weatherall ◽  
...  

Background. A novel, micromobile foot compression device (MMC) has been developed to reduce the risk of venous thromboembolism associated with prolonged seated immobility.Objective. To compare the efficacy of the MMC with graduated compression stockings in augmenting lower limb venous blood flow.Patients/Methods. Twenty participants were randomised to wear the MMC or a graduated compression stocking (GCS) on either the left or right leg while seated. Doppler ultrasound measurements of popliteal vein blood flow and leg circumference measurements were made-30and-10minutes (baseline) and +30 and +60 minutes following application of the interventions. The primary outcome variable was peak systolic velocity. A mixed linear model was used, with covariates including baseline measurement, randomised side, time, and a time by interaction term.Results. The mean popliteal vein peak systolic velocity at 60 minutes with the MMC was 20.1 cm/s which was significantly higher than with the GCS (difference 14.1 cm/s 95% CI 12.1–16.2), representing a 3.8-fold increase from baseline.Conclusion. The MMC resulted in a marked increase in lower limb venous blood flow which suggests that it may have efficacy in reducing the risk of venous thromboembolism associated with prolonged seated immobility, such as long distance air travel.


2015 ◽  
Vol 45 (1) ◽  
pp. 113-122 ◽  
Author(s):  
Ryszard Jasiński ◽  
Małgorzata Socha ◽  
Ludmiła Sitko ◽  
Katarzyna Kubicka ◽  
Marek Woźniewski ◽  
...  

Abstract Nordic walking and water aerobics are very popular forms of physical activity in the elderly population. The aim of the study was to evaluate the influence of regular health training on the venous blood flow in lower extremities and body composition in women over 50 years old. Twenty-four women of mean age 57.9 (± 3.43) years, randomly divided into three groups (Nordic walking, water aerobics, and non-training), participated in the study. The training lasted 8 weeks, with one-hour sessions twice a week. Dietary habits were not changed. Before and after training vein refilling time and the function of the venous pump of the lower extremities were measured by photoplethysmography. Body composition was determined by bioelectrical impedance. Eight weeks of Nordic walking training improved the venous blood flow in lower extremities and normalized body composition in the direction of reducing chronic venous disorder risk factors. The average values of the refilling time variable (p = 0.04, p = 0.02, respectively) decreased in both the right and the left leg. After training a statistically significant increase in the venous pump function index was found only in the right leg (p = 0.04). A significant increase in fat-free mass, body cell mass and total body water was observed (p = 0.01), whereas body mass, the body mass index, and body fat decreased (p < 0.03). With regard to water aerobic training, no similar changes in the functions of the venous system or body composition were observed.


2016 ◽  
Author(s):  
Bart Weijts ◽  
Edgar Gutierrez ◽  
Semion K Saikin ◽  
Ararat J Ablooglu ◽  
David Traver ◽  
...  

Arteries and veins are formed independently by different types of endothelial cells (ECs). In vascular remodeling, arteries and veins become connected and some arteries become veins. It is unclear how ECs in transforming vessels change their type and how fates of individual vessels are determined. In embryonic trunk, vascular remodeling transforms arterial intersegmental vessels (ISVs) into a functional network of arteries and veins. We found that, once an ISV is connected to venous circulation, venous blood flow promotes upstream migration of ECs that results in displacement of arterial ECs by venous ECs, completing the transformation of this ISV into a vein without trans-differentiation of ECs. Arterial blood flow initiated in two neighboring ISVs prevents their transformation into veins by activating Notch signaling in ECs. Together, different responses of ECs to arterial and venous blood flow lead to the formation of a balanced network with equal numbers of arteries and veins.


JAMA ◽  
1966 ◽  
Vol 198 (7) ◽  
pp. 784-785 ◽  
Author(s):  
A. Neistadt

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