Description of Guyton angiotensin module
Angiotensin
AN1:
This block damps the variations in rate of fluid flow in the renal tubules at
the macula densa (MDFLW). The damped outflow is the variable MDFLW3.
NB - REMOVED DAMPING FORM AN1!!!!
100
AN12, AN13, and AN14:
These blocks convert the rate of entry of angiotensin into the body fluids (ANPR1),
into the concentration of angiotensin (ANC) considering the normal value to be the
numeral 1. The value ANT is the time constant for rate of change of angiotensin
concentration in the body fluids. The value Z12 is a damping coefficient to allow
damping of this conversion so that the model can be run faster for long-term simulations.
keyword
AN19:
This block sets the lower limit to which ANU can fall (ANULL).
AN15:
This is an equation that allows one to convert the concentration of angiotensin (ANC)
into an angiotensin multiplier (ANM) which describes the multiplicative effect of
angiotensin on various physiological functions, assuming the normal value of ANM
to be 1.0. The value ANMUL is the upper limit to the level of ANM. ANMLL is the
lower limit of ANM. And the value ANCSNS is a sensitivity value for adjusting the
quantitative effect of ANC on ANM.
AN16, AN17, and AN18:
These blocks are a sensitivity controller for converting the basic effect of the
angiotensin multiplier (ANM) on other functional systems of the circulation (ANU).
The sensitivity adjustment is the factor ANUM in Block 17.
AN19:
This block sets the lower limit to which ANU can fall (ANULL).
Guyton
angiotensin
organ systems
cardiovascular circulation
physiology
This section calculates the control functions of angiotensin, beginning with the
control of angiotensin formation by the kidneys in response to changes in the rate
of flow of fluid in the renal tubules at the macula densa (MDFLW), and extending
through a series of curve-fitting and sensitivity controlled equations to determine
the multiple feedback effects of angiotensin to control the various aspects of
circulatory function.
AN11A:
This block allows the addition of infused angiotensin (ANGINF) to the amount of
angiotensin that is formed in the body (ANPR).
AN11B:
This block allows one to disregard all the previous blocks and to set the total
rate of angiotensin entering the circulatory system (ANPR1) to a constant level, ANGKNS.
When ANGKNS is equal to zero or less, then Block 11B is ineffective.
AN15:
This is an equation that allows one to convert the concentration of angiotensin (ANC)
into an angiotensin multiplier (ANM) which describes the multiplicative effect of
angiotensin on various physiological functions, assuming the normal value of ANM
to be 1.0. The value ANMUL is the upper limit to the level of ANM. ANMLL is the
lower limit of ANM. And the value ANCSNS is a sensitivity value for adjusting the
quantitative effect of ANC on ANM.
AN2:
This block calculates the formation rate of angiotensin (ANGSCR) at different
levels of MDFLW3.
100000
2008-00-00 00:00
AN9:
Summation of instantaneous formation of angiotensin (ANGSCR) plus the time delayed
formation of angiotensin (ANX1).
AN10:
Calculation of the total rate of formation of angiotensin (ANPR) in case some of
the renal mass (and therefore some of the JG cells) has been removed or destroyed.
Factor REK is equal to the proportion of kidney mass that is still functional.
10000
100
AN4, AN5, AN6, AN7, and AN8:
Calculation of additional formation of angiotensin caused after a long-term delay.
That is, when the JG cells are stimulated over long periods of time, in addition to
their acute effects on secretion rate of renin and subsequent formation of angiotensin,
there is a long-term increase in numbers of active JG cells to give a long-term delayed
response over a period of days. The variable ANXM adjusts the magnitude of this
delayed response. ANX is the total response without regard to the time delay. ANV is
the time-constant of the time delay. ANX1 is the total extra secretion after factoring
in the time delay effects of blocks 6, 7, and 8.
AN1:
This block damps the variations in rate of fluid flow in the renal tubules at
the macula densa (MDFLW). The damped outflow is the variable MDFLW3.
NB - REMOVED DAMPING FORM AN1!!!!
AN2:
This block calculates the formation rate of angiotensin (ANGSCR) at different
levels of MDFLW3.
AN4, AN5, AN6, AN7, and AN8:
Calculation of additional formation of angiotensin caused after a long-term delay.
That is, when the JG cells are stimulated over long periods of time, in addition to
their acute effects on secretion rate of renin and subsequent formation of angiotensin,
there is a long-term increase in numbers of active JG cells to give a long-term delayed
response over a period of days. The variable ANXM adjusts the magnitude of this
delayed response. ANX is the total response without regard to the time delay. ANV is
the time-constant of the time delay. ANX1 is the total extra secretion after factoring
in the time delay effects of blocks 6, 7, and 8.
AN20, AN21, and AN22:
Calculation of the effect of angiotensin on venous constriction (ANUVN), with
sensitivity controlled by ANUVM in Block 21.
AN12, AN13, and AN14:
These blocks convert the rate of entry of angiotensin into the body fluids (ANPR1),
into the concentration of angiotensin (ANC) considering the normal value to be the
numeral 1. The value ANT is the time constant for rate of change of angiotensin
concentration in the body fluids. The value Z12 is a damping coefficient to allow
damping of this conversion so that the model can be run faster for long-term simulations.
AN20, AN21, and AN22:
Calculation of the effect of angiotensin on venous constriction (ANUVN), with
sensitivity controlled by ANUVM in Block 21.
AN4, AN5, AN6, AN7, and AN8:
Calculation of additional formation of angiotensin caused after a long-term delay.
That is, when the JG cells are stimulated over long periods of time, in addition to
their acute effects on secretion rate of renin and subsequent formation of angiotensin,
there is a long-term increase in numbers of active JG cells to give a long-term delayed
response over a period of days. The variable ANXM adjusts the magnitude of this
delayed response. ANX is the total response without regard to the time delay. ANV is
the time-constant of the time delay. ANX1 is the total extra secretion after factoring
in the time delay effects of blocks 6, 7, and 8.
AN11:
This sets the lower limit of ANPR to a very low level, almost zero, below which
this cannot fall. The reason for this is to prevent a negative value from appearing.
AN16, AN17, and AN18:
These blocks are a sensitivity controller for converting the basic effect of the
angiotensin multiplier (ANM) on other functional systems of the circulation (ANU).
The sensitivity adjustment is the factor ANUM in Block 17.
Guyton
AN11A:
This block allows the addition of infused angiotensin (ANGINF) to the amount of
angiotensin that is formed in the body (ANPR).
AN11B:
This block allows one to disregard all the previous blocks and to set the total
rate of angiotensin entering the circulatory system (ANPR1) to a constant level, ANGKNS.
When ANGKNS is equal to zero or less, then Block 11B is ineffective.
AN9:
Summation of instantaneous formation of angiotensin (ANGSCR) plus the time delayed
formation of angiotensin (ANX1).
AN10:
Calculation of the total rate of formation of angiotensin (ANPR) in case some of
the renal mass (and therefore some of the JG cells) has been removed or destroyed.
Factor REK is equal to the proportion of kidney mass that is still functional.
AN11:
This sets the lower limit of ANPR to a very low level, almost zero, below which
this cannot fall. The reason for this is to prevent a negative value from appearing.
Encapsulation grouping component containing all the components in the Angiotensin Model. The inputs and
outputs of the Angiotensin Model must be passed by this component.