An evolutionary perspective on the origin of the cardiovascular system of vertebrates

2018 ◽  
Author(s):  
Roelof-Jan Oostra ◽  
Bjarke Jensen ◽  
Antoon F.M. Moorman
Keyword(s):  
Blood Flow ◽  
Cardiovascular System ◽  
Pacemaker Activity ◽  
Vascular Pattern ◽  
Evolutionary Perspective ◽  
Heart Tube ◽  
Basal Chordates ◽  
Vertebrate Embryo

The origin of the cardiovascular system of vertebrates is inferred from comparisons of basal chordates but must also encompass bewildering discrepancies. Basal chordates like lancelets (cephalochordates) have a vascular pattern similar to that of a vertebrate embryo, but without a recognizable heart or myocardium. Instead, the ‘venous’ part of their circulation contains contractile vessels, located upstream and downstream of the liver. Tunicates (urochordates) have a tubular heart containing cardiomyocytes and enclosed by a pericardium. Their circulation is open and the dominant pacemaker activity can be at either end of the heart tube, causing blood flow to reverse periodically. Recent molecular investigations have proved that urochordates rather than cephalochordates are the closest living relatives of vertebrates. This implies that the cardiovascular peculiarities of lancelets may be primitive ancestral qualities and that the original building plan of the vertebrate circulation featured a post-hepatic as well as a pre-hepatic cardiac pump.

scholarly journals A plumber’s guide to the cardiovascular system

2020 ◽  
Vol 44 (2) ◽  
pp. 163-168 ◽  
Author(s):  
Shannon E. Washburn ◽  
Randolph H. Stewart
Keyword(s):  
Heart Failure ◽  
Heart Rate ◽  
Blood Flow ◽  
Cardiovascular System ◽  
Interactive Teaching ◽  
Teaching Laboratory ◽  
Clinical Correlates ◽  
Student Volunteers ◽  
Flow Through ◽  
Student Discussion

Blood flow through the cardiovascular system is governed by the same physical rules that govern the flow of water through domestic plumbing. Using this analogy in a teaching laboratory, a model of the cardiovascular system constructed of pumps and pipes was used to demonstrate the basic interactions of pressure, flow, and resistance in a regulated system, with student volunteers providing the operational actions and regulatory components. The model was used to validate predictions and explore solutions prompted by student discussion. This interactive teaching laboratory provides an engaging experiential exercise that demonstrates regulation of flow and pressure in an intact cardiovascular system with apposite changes in heart rate and resistance. In addition, the system provides strong clinical correlates and illustrates how that regulated system responds to challenges such as heart failure, inappropriate vasodilation, and hemorrhage. The results demonstrate that, with limited practice, the instructor can effectively guide the students to reliably reproduce physiologically appropriate results.

Measurement of Blood Flow and Perfusion in the Cardiovascular System

1992 ◽  
Vol 27 ◽  
pp. S66-S71 ◽  
Author(s):  
CHARLES B. HIGGINS ◽  
GARY CAPUTO ◽  
MICHAEL F. WENDLAND ◽  
MAYTHEM SAEED
Keyword(s):  
Blood Flow ◽  
Cardiovascular System

scholarly journals Computational Modeling of Blood Hydrodynamics and Blockage Formation Phenomena in the Human Cardiovascular System

2010 ◽  
Vol 4 (2) ◽  
Author(s):  
Adrian Tentner ◽  
Georgy Guria ◽  
Andrey Ioilev ◽  
Simon Lo ◽  
Andros Onoufriou ◽  
...  
Keyword(s):  
Blood Flow ◽  
Porous Media ◽  
Cardiovascular System ◽  
Circulatory System ◽  
System Model ◽  
Porous Media Flow ◽  
Cfd Model ◽  
Human Cardiovascular System ◽  
Organ Models ◽  
The Impact

An international collaborative effort to develop a computational fluid dynamics (CFD) model of the human cardiovascular system (HCVS) has been initiated in 2008. The HCVS model is designed to describe (a) the blood flow hydrodynamics and associated heat transport phenomena, (b) the blood flow interactions with the essential organs, and (c) the vessel blockage formation associated with atherosclerosis and thrombosis. The CFD-HCVS model is being developed as a new specialized software module using as a foundation the CFD code, STAR-CD, that is developed and distributed by CD-adapco, Ltd., a member of the project team. The CFD-HCVS module includes the following components and capabilities. (1) A simplified 3D coarse mesh CFD model of the HCVS, which allows the simulation of hemodynamic transient phenomena. The circulatory system model is closed with porous-media flow components having a hydraulic resistance equivalent to the lumped flow resistance of the smaller vessels, including microcirculation. Both hydrodynamic and thermodynamic phenomena are described, allowing the study of blood flow transients in the presence of temperature changes. (2) Simplified zero-dimensional models of the essential organs (e.g., heart, kidneys, brain, liver, etc.) describing the time-dependent consumption or production of various blood components of interest. The organ models exchange information with the CFD system model through interfaces designed to allow their replacement, in the future, with more complex 3D organ models. (3) Selected sections of the circulatory system can be replaced by realistic 3 fine mesh vessel models allowing the detailed study of the 3D blood flow field and the vascular geometry changes due to blockage formation. (4) Models of local blockage formation due to atherosclerosis and thrombosis. Three HCVS models of increasing complexity have been designed. These models contain 27 vessels, 113 vessels, and 395 vessels. The initial CFD-HCVS model development is based on the medium HCVS model with 113 vessels. A closed circuit CFD model describing the major vessels and containing 0D models of the heart and kidneys has been developed. The CFD-HCVS model includes porous-media models describing the blood flow in the smaller vessels and capillaries. Initial simulations show that the calculated blood flow rates in the vessels modeled are in reasonably good agreement with the corresponding physiological values. A simplified model of thrombosis has also been developed. Current development efforts are focused on the addition of new vessels and 0D organ models and the development of atherosclerosis models. The HCVS model provides a flexible and expandable modeling framework that will allow the researchers from universities, research hospitals and the medical industry to study the impact of a wide range of phenomena associated with diseases of the circulatory system and will help them develop new diagnostics and treatments.

A Numerical Multiscale Study of the Haemodynamics in an Image-Based Model of Human Carotid Artery Bifurcation

2009 ◽  
Author(s):  
Diego Gallo ◽  
Raffaele Ponzini ◽  
Filippo Consolo ◽  
Diana Massai ◽  
Luca Antiga ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Blood Flow ◽  
Shear Stress ◽  
Wall Shear Stress ◽  
Cardiovascular System ◽  
Vessel Wall ◽  
3D Model ◽  
Carotid Bifurcation ◽  
Wall Shear ◽  
Flow Division

The initiation and progression of vessel wall pathologies have been linked to disturbances of blood flow and altered wall shear stress. The development of computational techniques in fluid dynamics, together with the increasing performances of hardware and software allow to routinely solve problems on a virtual environment, helping to understand the role of biomechanics factors in the healthy and diseased cardiovascular system and to reveal the interplay of biology and local fluid dynamics nearly intractable in the past, opening to detailed investigation of parameters affecting disease progression. One of the major difficulties encountered when wishing to model accurately the cardiovascular system is that the flow dynamics of the blood in a specific vascular district is strictly related to the global systemic dynamics. The multiscale modelling approach for the description of blood flow into vessels consists in coupling a detailed model of the district of interest in the framework of a synthetic description of the surrounding areas of the vascular net [1]. In the present work, we aim at evaluating the effect of boundary conditions on wall shear stress (WSS) related vessel wall indexes and on bulk flow topology inside a carotid bifurcation. To do it, we coupled an image-based 3D model of carotid bifurcation (local computational domain), with a lumped parameters (0D) model (global domain) which allows for physiological mimicking of the haemodynamics at the boundaries of the 3D carotid bifurcation model here investigated. Two WSS based blood-vessel wall interaction descriptors, the Time Averaged WSS (TAWSS), and the Oscillating Shear Index (OSI) were considered. A specific Lagrangian-based “bulk” blood flow descriptor, the Helical Flow Index (HFI) [2], was calculated in order to get a “measure” of the helical structure in the blood flow. In a first analysis the effects of the coupled 0D models on the 3D model are evaluated. The results obtained from the multiscale simulation are compared with the results of simulations performed using the same 3D model, but imposing a flow rate at internal carotid (ICA) outlet section equal to the maximum (60%) and the minimum (50%) flow division obtained out from ICA in the multiscale model simulation (the presence of the coupled 0D model gives variable internal/external flow division ratio during the cardiac cycle), and a stress free condition on the external carotid (ECA).

scholarly journals A REVIEW: ANGIOGRAPHY AND ANGIOPLASTY

2020 ◽  
Vol 9 (2) ◽  
Author(s):  
Md Zeeshan ◽  
Deshbandhu Joshi
Keyword(s):  
Cardiovascular Disease ◽  
Blood Flow ◽  
Cardiovascular System ◽  
Blood Vessels ◽  
Heart Attack ◽  
The Body ◽  
X Rays ◽  
Thin Tube ◽  
Flow Through ◽  
Heart Blood

The cardiovascular system refers to the heart, blood vessels and the blood. Blood contains oxygen and other nutrients which your body needs to survive. The body takes these essential nutrients from the blood. Angiography is an imaging test that uses X-rays to view your body's blood vessels. The X-rays provided by an angiography are called angiograms. This test is used to study narrow, blocked, enlarged, or malformed arteries or veins in many parts of your body, including your brain, heart, abdomen, and legs. Angioplasty is a procedure to restore blood flow through the artery. You have angioplasty in a hospital. The doctor threads a thin tube through a blood vessel in the arm or groin up to the involved site in the artery. The tube has a tiny balloon on the end. Cardiovascular disease generally refers to conditions that involve narrowed or blocked blood vessels that can lead to a heart attack, chest pain (angina) or stroke. Other heart conditions, such as those that affect your heart's muscle, valves or rhythm, also are considered forms of heart disease. Keyword: cardiovascular system, angiography, angioplasty

scholarly journals The ocular cardiac reflex effect study on cardiac hemodynamic parameters in healthy young mans.

2019 ◽  
Vol 40 (1) ◽  
pp. 17-24
Author(s):  
A. I. Palamarchuk
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Blood Flow ◽  
Cardiovascular System ◽  
Peripheral Resistance ◽  
Blood Flow Rate ◽  
Effect Study ◽  
Nonlinear Dependence ◽  
System Response ◽  
Hemodynamic Parameters

Purpose of the study. Investigate changes of cardiac hemodynamic parameters caused by ocular cardiac reflex triggering in healthy men’s in youthful age.Material and methods. 120 healthy male volunteers in youthful age were examined. The mean age was (19,2 ± 0,93 years). For ocular-cardiac reflex (OCR) triggering we used a patented model «Device for dosed compression effects on the eyeballs» and «The method of ocular cardiac reflex triggering». On the basis of the obtained parameters of systolic (SBP) and diastolic (DBP) blood pressure, by arithmetic operations, pulse pressure (PP) and average flow pressure (AFP) and integrative parameters of cardiohemodynamics (CHD) – systolic blood volume (SBV), minute blood flow volume (MBFV), volumetric blood flow rate (V), total peripheral resistance (TPR) were determined. Results. Three main types of cardiovascular system response on OCR triggering were identified. The first type – hypertensive (n = 30 (25%) of the total number of examined subjects) was characterized by a significant (p < 0,05) increase in heart rate, SBP, DBP, PP, AFP and other integrative parameters of CHD. The second, hypotonic type of the response (62 subjects; 51,7%) was characterized by a significant (p < 0,05) decrease in SBP, DBP, PP, AFP. Patients with third, dystonic type, of response (n = 28 (23,3%) of the total number examined subjects) showed significant bilateral changes of blood pressure parameters in a nonlinear dependence of compression power on the eyeballs. Determination CHD parameters directly after and 3 and 5 minutes after decompression of the air in the compression device we enabled to determine the subtype of the mobility of the nervous centers as a feature that complements the basic type. The subtype of normal mobility was revealed in 63,3% (n = 19) of subjects with the main hypertensive type of response, 69,3% (n = 43) of subjects with the main hypotonic and 60,7 % (n = 17) with the main dystonic type of response of the cardiovascular system. The inert subtype in the mobility of the cardiovascular system were identified in 36,7% (n = 11) individuals with hypertension is the main type of response, at 30,7% (n = 19) of individuals with primary hypotonic type of response and 39,3 % (n = 11) – distancing. The obtained typological changes in blood pressure parameters caused by OCR triggering allowed to reveal predisposition to hypertension, hypotension, dystonia and to predict the development of hypertension in patients with hypertensive type of response usin appropriate primary prevention changes in life style. The highest risk of hypertension development may be in persons with hypertensive inert type of reaction of the system of regulation of blood pressure on OCR triggering. Further studies are being conducted to confirm this assumption. Keywords: oculo-cardiac reflex, blood pressure, heart rate, young age.

Hemodynamics in awake rabbits during hyperbaric helium-oxygen exposure

1980 ◽  
Vol 48 (2) ◽  
pp. 281-283 ◽  
Author(s):  
L. E. Boerboom ◽  
J. N. Boelkins
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Blood Flow ◽  
Cardiac Output ◽  
Cardiovascular System ◽  
Systemic Vascular Resistance ◽  
Elevated Pressure ◽  
Inert Gases ◽  
Gas Mixture ◽  
Organ Blood Flow

Although man is being exposed to hyperbaric environments more frequently, the effects of these environments and the inert gases used are not clearly defined. We therefore designed an experiment to examine both the effects of helium and elevated pressure on the cardiovascular system in conscious rabbits exposed to normoxic levels of a helium-oxygen (He-O2) gas mixture at 1 and 11 atmospheres absolute (ATA) for 2 h. Variables studied included heart rate, blood pressure, cardiac output, systemic vascular resistance, organ blood flow, and resistance to flow. The only change observed was a decrease in heart rate from a control of 284 +/- 7 (mean +/- SE) to 246 +/- 12 beats/min after 2 h of breathing He-O2 at 1 ATA. We therefore conclude that the cardiovascular system is not adversely affected by helium or elevated pressure as used in this experiment.

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