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485
Advances in Social Sciences Research Journal – Vol.7, No.11
Publication Date: November 25, 2020
DOI:10.14738/assrj.711.9420.
Vincze, J., Vincze-Tiszay, G., & Szakacs, J. (2020). The Biophysical Modeling of the Hemodynamic in the Human Organism. Advances in
Social Sciences Research Journal, 7(11) 485-493.
The Biophysical Modeling of the Hemodynamic in the Human
Organism
Janos Vincze
1Health Human International Environment Foundation,
Budapest, Hungary
Gabriella Vincze-Tiszay
1Health Human International Environment Foundation,
Budapest, Hungary
Julianna Szakacs
George Emil Palade University of Medicine, Pharmacy,
Science and Technology of Targu Mures, Faculty of Medicine,
Department of Biophysics, Romania
ABSTRACT
The circulatory apparatus has as a main function the constant
maintaining of the internal environment in all the regions of the
organism. The blood is a liquid tissue, being formed of a fundamental
substance – plasma and blood cells. Heart is the central organ of the
cardiovascular apparatus. The heart muscles have numerous
biophysical properties. The cardiac muscle is never tired unless it
suffered a pathological process. During the diastole, blood is aspired in
the heart and during the systole it is pushed in the big and small
circulation. The blood amount pushed from the heart in the vascular
system in a certain time represents the blood flow. The biophysical
methods are next: we administer a certain substance amount, then its
passing speed will depend on its concentration; to apply the
calorimetric principles for the measurement of the gastric blood flow;
the diagnostic of a chronic peripheral arteriopathy we use the
calorimetric method is based on measuring the heat being introduced in
a certain amount of water which has known temperature; one of the
most often used methods for the evaluation of the use of radioisotopes
in the cardio-vascular system is the compartment method. Any attempt
to apply biophysics to the life systems involves three stages. First we
observe the phenomena and formulate a biophysical description in the
form of equations; after to solve the equations. Finally we return to the
real life system and interpret this solution in terms of reality, this
interpretation may requiew experimental testing.
Keywords: biophysical modelling. hemodynamic, circulatory apparatus,
calorimetric principles, arteriopathy
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Advances in Social Sciences Research Journal (ASSRJ) Vol.7, Issue 11, November-2020
INTRODUCTION
The human organism behaves like a morphofunctional unit in the continuous process of adaptation
to the environment. The organism’s unity is not given by its homogeneity, but on the contrary, by
its highest heterogeneity. From the sub-cellular structural-functional levels, step after step, to the
ultimate level – the organism – heterogeneity amplifies, which requires more and more complex
adjustment mechanisms, with more and more complex interrelations. [1]
The circulatory apparatus is made of a central muscular cavity organ adapted to the function of
blood propulsion – the heart and a vascular system. The vascular system is a closed tubular system,
made of a series of pipes, structurally adapted to the function of blood propulsion and circulation.
It is represented by arteries, capillaries, veins and lymph vases. [2]
All the vases are padded internally with an endothelium which is surrounded according to certain
specific mechanical and hemodynamic conditions which will form together the vascular wall. These
structures are: collagen and reticulate fibres, elastic fibres, smooth muscular fibres. The vases are
dynamic structures characterized by a great plasticity and adaptive capacity, their structure being
partially dependent on the functional state of those organs. This fact explains the modification in
biophysical limits of the vases in the pregnant uterus, in the lactating mammal gland, in the atrophic
glands. The capillaries are represented by very thin canals with a diameter between 4–30 μm. These
structures are present in all the organs and tissues under the aspect of variable size and form
networks according to the morphofunctional features of that organ. The capillary vases as
morphofunctional units have a great plastic and regenerative capacity. [3]
The capillary walls have a specific property, which is permeability. The capillary as
morphofunctional unit represents a biological membrane with selective permeability. The
exchanges between blood and tissues can be obtained in the following ways: a) passive
transportation due to the concentration difference, this way water and small molecules can pass
though; b) active transfer which is obtained through pinocytosis and endocytosis; c) the
interendotelial transport at the pore level. In the composition of the vascular tree there are two
circulation territories: great circulation and small circulation. [4]
The blood amount pushed from the heart in the vascular system in a certain time represents the
blood flow. The blood volume that the hearts pushes in the arteries in a contraction is called systolic
volume and normally it is 50–80 cm3. The blood volume that the heart pushes in the vessels during
a minute is called minute-volume (5000 cm3).
If we compress an artery with the finger, we can feel those rhythmical movements called pulsations.
They coincide with the cardiac systoles which propagate along the arteries walls with a higher speed
(5m/s) then the blood circulation speed. If we follow the pulse we can count the cardiac
contractions.
BIOPHYSICAL MODELING
With modeling we usually understand the reproduction of the behaviour of a system on an analogue
one especially built on the basis of certain rules. Usually, the system is modelled either on a physical
one, either on a mathematical one. The mathematic model has the advantage of comfort and
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URL: http://dx.doi.org/10.14738/assrj.711.9420 487
Vincze, J., Vincze-Tiszay, G., & Szakacs, J. (2020). The Biophysical Modeling of the Hemodynamic in the Human Organism. Advances in Social Sciences
Research Journal, 7(11) 485-493.
economy. The mathematic dealing mode also eases significantly the discovery of the analogies
between the various systems.
Generally, for the study mode of the biophysical systems, two methods are foreseen: the
phenomenological methods and static methods. The phenomenological method studies the
phenomena regarding a few fundamental principles that result from various experiences, leaving
aside the discreet internal structure of the matter. [5]
The statistic method studies the phenomena starting from the discreet internal structure of the
matter. For the study of the systems with an enormous number of particles the probability calcu- lation is used. Hence, the measurable macroscopic properties appear like average statistic values of
the properties of the individual elements.
The modeling method in biophysics consists of the creation of certain devices (models), with which
processes analogue with those happening in living organism are studied. The biophysical model
though abstract reasoning leads to models of the phenomena which by simplifying and isolating
some aspects of the phenomena discover laws and relationships which describe with a certain
approximation the behaviour or functioning of bodies or biological ensembles.
The biophysical models offer a „language” of quantitative and qualitative processing of
experimental data, being compatible and adequate to the laws of biology. One of the types of
modeling, the so called analogical modeling, consists of the study of a phenomena, which respects
certain mathematical laws, with the help of its resemblance with another simpler phenomenon,
subject to the same mathematical laws. As an example of analogies, we can quote the oscillation
processes with mechanical, acoustic, thermal, optic, electromagnetic, seismic, physiologic, even
economic character or the analogy between the nervous impulses and the electric impulses. [6]
The first electrograms were made by Eindhoven in 1903 at Leyden, using electrodes applied in the
bipolar deviation in three points on the body. The potentials collected with these electrodes
represent the projections of the cardiac vectors on the exploration axes. The amplitudes of the
vector at its turn is proportional with the electromotor force of the heart, whose size is a very
important diagnostic mean in the medical clinic for the assessment of the heart’s functioning state.
At normal state the electrocardiogram presents for each cycle a sequence of five waves denoted
with the letters P, Q, R, S T. Each of these waves represents the electric activity in the various phases
of the cardiac cycle.
BIOPHYSICAL METHODS
Further on, we present the modelling of the blood volume, if we administer a certain substance
amount, then its passing speed will depend on its concentration, hence the volume at which it
spreads in the deposit. [7] This size is hard to determine. This is why post defined the amount of
substance which would realise an initial concentration exactly defined in blood after the complete
resorbtion and after the installation of a supposed equilibrium as dose. This initial fictional
concentration in blood is denoted with c. It would be achieved at time t = 0, and at the time t the
concentration would be c*. Then results the analogy with the formula of c* increase in relation of
the reaction speed: