The pressure in the aorta changes throughout the cardiac cycle. During systole, as the heart contracts, the outflux of blood into the aorta causes an increase in pressure, whereas during diastole the pressure decreases as the heart relaxes. A simple model for the aortic pressure waveform is given by the Windkessel effect described by the image below. In this model, the heart is considered a pressure generating pump which is directly connected to an elastic compartment (the aorta), which in turn is connected to a rigid set of peripheral vessels (the hose of the firefighter). ● Pump ● Heart Air Windkessel In order to find the aortic pressure waveform from the Windkessel model, a mass balance formulation around the aorta must be formulated. Coming into the aorta from the heart we have the flowrate Q(t). According to conservation of mass, this inflow rate Q(t) must be equal to the outflow rate into the peripheral vessels and the change in volume of the aorta. To find these two relationships, the following assumptions must be made: Elastic arteries Assume the blood pressure in the aorta is given by p Assume that the change in volume (and therefore mass) in the aorta with respect to time is proportional to the change in pressure, p, with respect to time up to a proportionality constant K Assume that the outflow rate into the peripheral vessels is dependent on the resistance of those vessels R and the blood pressure in the aorta p. This outflow relationship follows a form like Ohm's Law, where the pressure is similar to the voltage and the flow similar to the current. Based on the assumptions described before, write the first order differential equation that describes the mass balance of the Windkessel model.

Human Anatomy & Physiology (11th Edition)
11th Edition
ISBN:9780134580999
Author:Elaine N. Marieb, Katja N. Hoehn
Publisher:Elaine N. Marieb, Katja N. Hoehn
Chapter1: The Human Body: An Orientation
Section: Chapter Questions
Problem 1RQ: The correct sequence of levels forming the structural hierarchy is A. (a) organ, organ system,...
icon
Related questions
Question
The pressure in the aorta changes throughout the cardiac cycle. During systole, as the heart contracts, the outflux
of blood into the aorta causes an increase in pressure,
whereas during diastole the pressure decreases as the
heart relaxes. A simple model for the aortic pressure
waveform is given by the Windkessel effect described by
the image below. In this model, the heart is considered a
pressure generating pump which is directly connected to
an elastic compartment (the aorta), which in turn is
connected to a rigid set of peripheral vessels (the hose of
the firefighter).
5
Pump
Heart
Air
Windkessel
Elastic arteries
In order to find the aortic pressure waveform from the Windkessel model, a mass balance formulation around the aorta
must be formulated. Coming into the aorta from the heart we have the flowrate Q(t). According to conservation of mass,
this inflow rate Q(t) must be equal to the outflow rate into the peripheral vessels and the change in volume of the aorta. To
find these two relationships, the following assumptions must be made:
Assume the blood pressure in the aorta is given by p
Assume that the change in volume (and therefore mass) in the aorta with respect to time is proportional to the
change in pressure, p, with respect to time up to a proportionality constant K
Assume that the outflow rate into the peripheral vessels is dependent on the resistance of those vessels R and the
blood pressure in the aorta p. This outflow relationship follows a form like Ohm's Law, where the pressure is
similar to the voltage and the flow similar to the current.
Based on the assumptions described before, write the first order differential equation that describes the
mass balance of the Windkessel model.
Transcribed Image Text:The pressure in the aorta changes throughout the cardiac cycle. During systole, as the heart contracts, the outflux of blood into the aorta causes an increase in pressure, whereas during diastole the pressure decreases as the heart relaxes. A simple model for the aortic pressure waveform is given by the Windkessel effect described by the image below. In this model, the heart is considered a pressure generating pump which is directly connected to an elastic compartment (the aorta), which in turn is connected to a rigid set of peripheral vessels (the hose of the firefighter). 5 Pump Heart Air Windkessel Elastic arteries In order to find the aortic pressure waveform from the Windkessel model, a mass balance formulation around the aorta must be formulated. Coming into the aorta from the heart we have the flowrate Q(t). According to conservation of mass, this inflow rate Q(t) must be equal to the outflow rate into the peripheral vessels and the change in volume of the aorta. To find these two relationships, the following assumptions must be made: Assume the blood pressure in the aorta is given by p Assume that the change in volume (and therefore mass) in the aorta with respect to time is proportional to the change in pressure, p, with respect to time up to a proportionality constant K Assume that the outflow rate into the peripheral vessels is dependent on the resistance of those vessels R and the blood pressure in the aorta p. This outflow relationship follows a form like Ohm's Law, where the pressure is similar to the voltage and the flow similar to the current. Based on the assumptions described before, write the first order differential equation that describes the mass balance of the Windkessel model.
Expert Solution
trending now

Trending now

This is a popular solution!

steps

Step by step

Solved in 3 steps

Blurred answer
Knowledge Booster
Respiratory system
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, biology and related others by exploring similar questions and additional content below.
Similar questions
  • SEE MORE QUESTIONS
Recommended textbooks for you
Human Anatomy & Physiology (11th Edition)
Human Anatomy & Physiology (11th Edition)
Biology
ISBN:
9780134580999
Author:
Elaine N. Marieb, Katja N. Hoehn
Publisher:
PEARSON
Biology 2e
Biology 2e
Biology
ISBN:
9781947172517
Author:
Matthew Douglas, Jung Choi, Mary Ann Clark
Publisher:
OpenStax
Anatomy & Physiology
Anatomy & Physiology
Biology
ISBN:
9781259398629
Author:
McKinley, Michael P., O'loughlin, Valerie Dean, Bidle, Theresa Stouter
Publisher:
Mcgraw Hill Education,
Molecular Biology of the Cell (Sixth Edition)
Molecular Biology of the Cell (Sixth Edition)
Biology
ISBN:
9780815344322
Author:
Bruce Alberts, Alexander D. Johnson, Julian Lewis, David Morgan, Martin Raff, Keith Roberts, Peter Walter
Publisher:
W. W. Norton & Company
Laboratory Manual For Human Anatomy & Physiology
Laboratory Manual For Human Anatomy & Physiology
Biology
ISBN:
9781260159363
Author:
Martin, Terry R., Prentice-craver, Cynthia
Publisher:
McGraw-Hill Publishing Co.
Inquiry Into Life (16th Edition)
Inquiry Into Life (16th Edition)
Biology
ISBN:
9781260231700
Author:
Sylvia S. Mader, Michael Windelspecht
Publisher:
McGraw Hill Education