Living Physics Portal: Modeling Flow through the Resistance Vessels

Abstract: Section 4 of the Physics of the Cardiovascular System investigates resistance factors in the smaller blood vessels. Students will: 1) analyze pressure drops that occur with position along the circulation cycle for a supine patient in the small resistance vessels; 2) use a physical model to investigate the resistance vessels of the circulatory system; and 3) apply the Hagen-Poiseuille Principle for resistance vessels and the parallel nature of the small branches of the circulatory system to an understanding of blood flow in health and disease.

Resource Types: In-class activity, Lecture materials, Lab, Demonstration, Instructor supplement, Restricted access, Pre-class assignment, Homework, Student reading

Authors:

Nancy Donaldson

Rockhurst University

Charles Gosselin

Rockhurst University

TOPICS

Physics Topics:

Fluid Mechanics > Dynamics of Fluids > Flow Rate, Hagen-Poiseuille Equation, Viscosity

Fluid Mechanics > Statics of Fluids > Static Pressure

Life Sciences Topics:

Cross-cutting Biological Concepts > Structure/Function Relationships > Elasticity

Human and Animal Physiology > Cardiovascular System > Cardiovascular Disorders, Healthy Cardiovascular Function

Math Topics:

Algebra; Geometry

FILES Download0

Physics of the Cardiovascular System - Five Section Module > Modeling Flow through the Resistance Vessels - Section 4 of 5

Modeling Flow through the Resistance Vessels - Section 4 of 5

4_Modeling the Resistance Vessels_INSTRUCTOR.docx

4_Modeling the Resistance Vessels_STUDENT.docx

4_Modeling the Resistance Vessels_INSTRUCTOR.docx

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INSTRUCTOR GUIDE

IMPLEMENTATION

Duration: 2 sessions of 50 minutes per session.

Equipment required: Everyday items; Standard physics equipment; Specialized physics equipment

Specific equipment needed: The author suggests hands-on active learning for best student understanding but, to save money or time, the curriculum can be easily modified to active learning paper-pencil instruction if construction of the apparatus proves prohibitive to curriculum use. For hands-on use, each group will need: - CVS Apparatus (See Section 6 of Physics of the Cardiovascular System Module for Parts List). Price ~ $400 (used in Sections 4 and 5 of the CVS module) - this section uses three different radii tubes as test sections - Absolute Pressure Sensor (Pasco) - $175 - Fluid Flow Sensor (Pasco) with Venturi Tube - $195 - Pasco Interface

Basic implementation tips & tricks: Section 4 is designed for students to directly investigate Hagen-Poiseuille Principle for resistance vessels and the parallel nature of the small branches of the circulatory system . The CVS Apparatus aids in understanding as students change resistance parameters in series/parallel flow circuits and relate dynamic changes to flow variables in the human circulatory system. The curriculum can be modified to active learning paper-pencil instruction if construction of the apparatus proves prohibitive. See Section 0 for more pedagogical information and tips on timing.

How does this resource fit into the flow of your course? This Resource is part of our Physics of the Body II course which students take as part of the Physics of Medicine Program. This is an "intermediate" physics course that pre-med and pre-physical therapy students take after completing their introductory physics class. With the proper student foundation, the resource could easily be used in an IPLS class.

PEDAGOGY

Pedagogical approach: Peer Instruction / Think-Pair-Share; Collaborative problem-solving; Conceptually-oriented activities; Context-rich problems; Ranking tasks; Guided inquiry; SCALE-UP / studio / workshop physics; Modeling Instruction; Mathematically-focused activities; Experimentally-focused activities

Skills / Competencies: Dimensional analysis; Functional dependence; Multiple representations; Estimation; Intuition building; Building models; Evaluating models; Performing experiments; Analyzing experimental data; Applying physical principles; Interdisciplinarity; Metacognitive skills

What insights or realizations do you hope students gain from this resource? Section 4 introduces the resistance factors of small blood vessels through the use of a hands-on model. The CVS Apparatus uses a heart (pump) in series with a test section of blood vessels. Pressure sensors measure pressure readings at various locations allowing students to determine the pressure drop causing flow rate across different test sections. In addition, the CVS Apparatus has a parallel branch which is designed for students to dynamically see the effects of branching on the pressure drop needed and flow rate. A tie up with the Equation of Continuity illustrates the benefit to nutrient exchange across blood vessels.

Why is this resource useful to life sciences students? The human body is a complicated system. Generating a strong understanding of the fluid static and dynamic pressure principles that guide the circulatory system will be valuable to students. Curriculum is based on learning the physics principles that guide structure and function of the CVS leading students to a deeper understanding of the role of physics in cardiovascular health and disease.

DISCUSSION

SUBMISSION DETAILS

License: CC: BY-NC-SA - Attribution, No Commercial uses and Share Alike. Derivative works must have the same license

Last Edit Date: January 25, 2019