Guyton Model: muscle_O2_delivery
Catherine
Lloyd
Auckland Bioengineering Institute, University of Auckland
Model Status
This CellML model has been validated. Due to the differences between procedural code (in this case C-code) and
declarative languages (CellML), some aspects of the original model were not able to be encapsulated by the CellML
model (such as the damping of variables). This may effect the transient behaviour of the model, however the
steady-state behaviour would remain the same. The equations in this file and the steady-state output from
the model conform to the results from the MODSIM program.
Model Structure
Arthur Guyton (1919-2003) was an American physiologist who became famous for his 1950s experiments in which he studied the
physiology of cardiac output and its relationship with the peripheral circulation. The results of these experiments
challenged the conventional wisdom that it was the heart itself that controlled cardiac output. Instead Guyton demonstrated
that it was the need of the body tissues for oxygen which was the real regulator of cardiac output. The "Guyton Curves"
describe the relationship between right atrial pressures and cardiac output, and they form a foundation for understanding
the physiology of circulation.
The Guyton model of fluid, electrolyte, and circulatory regulation is an extensive mathematical model of human circulatory
physiology, capable of simulating a variety of experimental conditions, and contains a number of linked subsystems relating
to circulation and its neuroendocrine control.
This is a CellML translation of the Guyton model of the regulation of the circulatory system. The complete model consists
of separate modules each of which characterise a separate physiological subsystems. The Circulation Dynamics is the primary
system, to which other modules/blocks are connected. The other modules characterise the dynamics of the kidney, electrolytes
and cell water, thirst and drinking, hormone regulation, autonomic regulation, cardiovascular system etc, and these feedback
on the central circulation model. The CellML code in these modules is based on the C code from the programme C-MODSIM created
by Dr Jean-Pierre Montani.
The tissues of the body are divided into non-muscle tissues and muscle tissues, and the delivery of oxygen to each one of these
is calculated separately. The principal reason for this separation is that during muscle activity, the delivery of oxygen to
the muscles increases tremendously and correspondingly affects the blood flow through the muscles. This particular CellML model
describes the delivery of oxygen to the muscle, and several aspects of local cellular usage of oxygen are also calculated.
model diagram
A systems analysis diagram for the full Guyton model describing circulation regulation.
model diagram
A schematic diagram of the components and processes described in the current CellML model.
There are several publications referring to the Guyton model. One of these papers is cited below:
Circulation: Overall Regulation, A.C. Guyton, T.G. Coleman, and H.J. Granger, 1972,
Annual Review of Physiology
, 34, 13-44. PubMed ID: 4334846
Guyton
Muscle Oxygen Delivery
Description of Guyton muscle oxygen delivery module
2008-00-00 00:00
keyword
physiology
organ systems
cardiovascular circulation
muscle oxygen
Guyton
The tissues of the body are divided into non-muscle tissues and muscle tissues,
and the delivery of oxygen to each one of these is calculated separately. The
principal reason for this separation is that during muscle activity, the delivery
of oxygen to the muscles increases tremendously and correspondingly affects the
blood flow through the muscles. Several aspects of local cellular usage of oxygen
are also calculated.
57.064
0
39.9701
0
48.0702
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38.0558
0
57.1
0
38.0
0
0.699673
0
Encapsulation grouping component containing all the components in the Muscle Oxygen Delivery Model.
The inputs and outputs of the Muscle Oxygen Delivery Model must be passed by this component.
OM1:
The volume of oxygen in the arterial blood flowing to the muscles each minute (02ARTM)
is equal to the volume of oxygen in each liter of arterial blood (OVA) times the muscle
blood flow (BFM).
OM1:
The volume of oxygen in the arterial blood flowing to the muscles each minute (02ARTM)
is equal to the volume of oxygen in each liter of arterial blood (OVA) times the muscle
blood flow (BFM).
OM2:
The volume of oxygen in the venous blood flowing away from the muscles
each minute (O2VENM) is equal to the volume of blood flowing into the muscles
from the arteries (O2ARTM) minus the rate of uptake of oxygen by the muscles
per minute (RMO).
OM3 and OM4:
The venous oxygen saturation in the muscles (OVS) is equal to the volume of oxygen
transported to the muscle veins each minute (O2VENM) divided by the blood flow
through the muscles per minute (BFM), divided by the hematocrit of the blood (HM),
and divided by a constant that relates volume of oxygen in the blood to hematocrit.
Damping of the oxygen venous saturation (OVS) is provided by Block OM4 and is controlled
by the damping constant (Z6).
OM5 and OM5A:
The pressure of the oxygen in the venous blood of the muscles (PVO) is equal to the
saturation of the oxygen in the venous blood of the muscles (OVS) times a constant
and times a factor related exponentially (EXCXP2) to the level of exercise (EXC)
caused by changes in tissue fluid products that affect oxygen combination with
hemoglobin.
OM2:
The volume of oxygen in the venous blood flowing away from the muscles
each minute (O2VENM) is equal to the volume of blood flowing into the muscles
from the arteries (O2ARTM) minus the rate of uptake of oxygen by the muscles
per minute (RMO).
OM3 and OM4:
The venous oxygen saturation in the muscles (OVS) is equal to the volume of oxygen
transported to the muscle veins each minute (O2VENM) divided by the blood flow
through the muscles per minute (BFM), divided by the hematocrit of the blood (HM),
and divided by a constant that relates volume of oxygen in the blood to hematocrit.
Damping of the oxygen venous saturation (OVS) is provided by Block OM4 and is controlled
by the damping constant (Z6).
OM5 and OM5A:
The pressure of the oxygen in the venous blood of the muscles (PVO) is equal to the
saturation of the oxygen in the venous blood of the muscles (OVS) times a constant
and times a factor related exponentially (EXCXP2) to the level of exercise (EXC)
caused by changes in tissue fluid products that affect oxygen combination with
hemoglobin.
OM17, OM18, OM19, OM20, OM21, OM22, and OM23:
Calculation of the rate of metabolic usage of oxygen by the muscle cells (MMO)
from several factors: the oxygen pressure in the muscle cells (PMO), the basal
level of oxygen utilization by the muscle cells (OMM), the effect of autonomic
stimulation on muscle usage of oxygen (AOM), and the effect of exercise on the
metabolic usage of oxygen by the muscles (EXC). Blocks OM17 and OM18 cause the
metabolic usage of oxygen to reach a maximum at any time that the average muscle
cellular oxygen level is above the value of 38 mmHg pressure. The constants in
the various blocks are curve-shaping constants to relate cellular oxygen
pressure (PMO) to the metabolic usage of oxygen.
OM17, OM18, OM19, OM20, OM21, OM22, and OM23:
Calculation of the rate of metabolic usage of oxygen by the muscle cells (MMO)
from several factors: the oxygen pressure in the muscle cells (PMO), the basal
level of oxygen utilization by the muscle cells (OMM), the effect of autonomic
stimulation on muscle usage of oxygen (AOM), and the effect of exercise on the
metabolic usage of oxygen by the muscles (EXC). Blocks OM17 and OM18 cause the
metabolic usage of oxygen to reach a maximum at any time that the average muscle
cellular oxygen level is above the value of 38 mmHg pressure. The constants in
the various blocks are curve-shaping constants to relate cellular oxygen
pressure (PMO) to the metabolic usage of oxygen.
OM17, OM18, OM19, OM20, OM21, OM22, and OM23:
Calculation of the rate of metabolic usage of oxygen by the muscle cells (MMO)
from several factors: the oxygen pressure in the muscle cells (PMO), the basal
level of oxygen utilization by the muscle cells (OMM), the effect of autonomic
stimulation on muscle usage of oxygen (AOM), and the effect of exercise on the
metabolic usage of oxygen by the muscles (EXC). Blocks OM17 and OM18 cause the
metabolic usage of oxygen to reach a maximum at any time that the average muscle
cellular oxygen level is above the value of 38 mmHg pressure. The constants in
the various blocks are curve-shaping constants to relate cellular oxygen
pressure (PMO) to the metabolic usage of oxygen.
OM6:
The pressure gradient for delivery of oxygen from the muscle capillaries to the
muscle cells (PGRM) is equal to the pressure of the oxygen remaining in the
muscle venous blood (PVO) minus the pressure of the oxygen in the muscle cells (PMO).
OM8:
Rate of delivery of oxygen to the muscles (RMO) is equal to the blood flow to
the muscles (BFM) times the pressure gradient between the muscle capillary blood
and the muscle cells (PGRM) times a constant (PM5) that can be varied to represent
such factors as changes in muscle capillarity or so forth.
OM6:
The pressure gradient for delivery of oxygen from the muscle capillaries to the
muscle cells (PGRM) is equal to the pressure of the oxygen remaining in the
muscle venous blood (PVO) minus the pressure of the oxygen in the muscle cells (PMO).
OM8:
Rate of delivery of oxygen to the muscles (RMO) is equal to the blood flow to
the muscles (BFM) times the pressure gradient between the muscle capillary blood
and the muscle cells (PGRM) times a constant (PM5) that can be varied to represent
such factors as changes in muscle capillarity or so forth.
OM9:
The rate of change of stored oxygen in the muscle (DO2M) is equal to the
rate of delivery of oxygen to the muscles by the blood (RMO) minus the rate
of metabolic usage of oxygen by the muscle cells (MMO).
OM10:
The instantaneous volume of oxygen dissolved in all of the muscles (QOM) is
calculated by integrating with respect to time the rate of change of oxygen
in the muscles (DO2M).
OM11:
This sets a lower limit for QOM in the muscle tissue.
OM9:
The rate of change of stored oxygen in the muscle (DO2M) is equal to the
rate of delivery of oxygen to the muscles by the blood (RMO) minus the rate
of metabolic usage of oxygen by the muscle cells (MMO).
OM10:
The instantaneous volume of oxygen dissolved in all of the muscles (QOM) is
calculated by integrating with respect to time the rate of change of oxygen
in the muscles (DO2M).
OM11:
This sets a lower limit for QOM in the muscle tissue.
OM12:
Calculation of the pressure of oxygen in the muscle cells (PMO) from the
volume of oxygen in the muscles (QOM).
OM12:
Calculation of the pressure of oxygen in the muscle cells (PMO) from the
volume of oxygen in the muscles (QOM).