Calling 911: The Physics of Calling 911: The Physics of Heart and Lung FunctionHeart and Lung Function

Seth BlumbergSeth BlumbergUniversity of MichiganUniversity of Michigan

Physics Department / Medical SchoolPhysics Department / Medical School

www.umich.edu/~sblumberwww.umich.edu/~sblumber

Public LecturesPublic Lectures

Ta-You Wu Lecture Ta-You Wu Lecture Sir Martin Rees: Where is Cosmology Going?Sir Martin Rees: Where is Cosmology Going?Wed. Nov 12 at 4pm, East Hall AuditoriumWed. Nov 12 at 4pm, East Hall Auditorium

2525thth Distinguished Faculty Lecture Distinguished Faculty LectureHomer Neil: The CERN Large Hadron ColliderHomer Neil: The CERN Large Hadron ColliderWed. Nov 19 at 4pm, 340 West HallWed. Nov 19 at 4pm, 340 West Hall

An X-ray Anniversary!An X-ray Anniversary!

Courtesy of Perry Pernicano M.D.

From Cancer to Medical SchoolFrom Cancer to Medical School

Cancer changed my life, but it did nothing to my love of physics!

LungLung

www.louisville.edu/medschool/physiology/

http://www.electrosols.com

Lung FunctionLung Function

http://www.jamesline.com

Quiz Time!Quiz Time!

The surface area of the interior of an adultThe surface area of the interior of an adult

lung is closest to: lung is closest to: A.A. 1 square meter1 square meter

B.B. 5 square meters5 square meters

C.C. 20 square meters20 square meters

D.D. 100 square meters100 square meters

Hint:Hint: There are about 300 million alveoli (each There are about 300 million alveoli (each

about .1mm in radius)about .1mm in radius)

Weight of Air DemoWeight of Air Demo

M1

Weight

Buoyancy

M1

Vacuum

M2 M2

Pressure Varies with HeightPressure Varies with Height

www.npl.co.uk

0

Mgy

RTp p e

Denver

Mount Everest

Atmospheric Pressure & Atmospheric Pressure & TuberculosisTuberculosis

www.electrosols.comwww.adventures.com

Atmospheric PressureAtmospheric Pressure

ww2010.atmos.uiuc.edu

Punctured Chest = PneumothoraxPunctured Chest = Pneumothorax

From Human Physiology Rhoades & pflanzer, 2nd edition

Surface TensionSurface Tension

bio.bio.rpi.edu/Parsons http://home.earthlink.net

Quiz Time!Quiz Time!

What is going to happen?What is going to happen?A.A. The bubbles will become equal size.The bubbles will become equal size.B.B. The large bubble will collapse into the smaller The large bubble will collapse into the smaller

bubblebubbleC.C. The small bubble will collapse into the larger The small bubble will collapse into the larger

bubblebubbleD.D. The bubble sizes will oscillate back and forthThe bubble sizes will oscillate back and forth

Surface Tension of a BubbleSurface Tension of a Bubble

bio.bio.rpi.edu/Parsons

Key Point:Smaller bubbles have a larger pressure differential

LungLung

www.louisville.edu/medschool/physiology/

http://www.electrosols.com

The Physics of EmphysemaThe Physics of Emphysema

Surface Tension plays a major role in the life of 3 Surface Tension plays a major role in the life of 3 million Americans!million Americans!

ww2.mcgill.ca/pathologyeducation.vetmed.vt.edu

Surfactants Decrease Surface Surfactants Decrease Surface TensionTension

Lung Surfactants play an important role in Lung Surfactants play an important role in Premature BirthPremature Birth

bio.bio.rpi.edu/Parsons

HeartHeart

sprott.physics.wisc.edu/

Gravitation can not be held responsible for people falling in love

- Albert Einstein

HeartHeart

http://www.cts.usc.edu/

MRI of Beating HeartMRI of Beating Heart

Movie provided Benoit Desjardins M.D.

Heart Facts:- Pumps 1-2 gallons of fluid every minute- Generates pressures up to 4 lbs per sq. inch- 25 – 50 million cycles / year- Monitors it’s own function via internal circuitry

The total cross-sectional area of the vessels increases with tance from the heart.

Consequently, the velocity of flow decreases, and then increases after passing the capillaries.

Blood FlowBlood Flow

www.colby.edu/biology

Poiseuille FlowPoiseuille Flow

Resistance is highly sensitive to diameter of Resistance is highly sensitive to diameter of vessels.vessels. 4

8

rQ p

L

4

1R

r

Quiz Time!Quiz Time!

If I add a resistor to the circuit, the currentIf I add a resistor to the circuit, the current

from the battery will?from the battery will?A.A. DecreaseDecrease

B.B. IncreaseIncrease

C.C. It depends on how I attach the resistorIt depends on how I attach the resistor

D.D. None of the above - The battery will explodeNone of the above - The battery will explode

R1

Series & Parallel ResistanceSeries & Parallel Resistance

R1

R2

1/Req = 1/R1 + 1/R2

R2R1

Req = R1 + R2

Fetal and Neonatal CirculationFetal and Neonatal Circulation

R1(Lung)

R2 (Bypass)

1/Req = 1/R1 + 1/R2

Before birth R1 is high. Thus most of blood

bypasses the lung.

After birth R1 decreases and blood is directed through the lungs.

Fetal and Neonatal CirculationFetal and Neonatal Circulation

http://bio.bio.rpi.edu/Parsons

Resistance plays an important role in a baby’s first breath!

Pressure Waves cause aneurysmsPressure Waves cause aneurysms

Quiz Time!Quiz Time!

Fighter Pilot g-suits are mostFighter Pilot g-suits are most

similar to a mechanism found in:similar to a mechanism found in:

A.A. GiraffesGiraffes

B.B. FishFish

C.C. BirdsBirds

D.D. None of the above. G-None of the above. G-suits are for looks onlysuits are for looks only

microgravity.grc.nasa.gov

Bernoulli’s PrincipleBernoulli’s Principle

www.artsafaris.co.ke

21

2extP v gh

constant

Other Physics in MedicineOther Physics in Medicine

ElectrophysiologyElectrophysiology DiffusionDiffusion Muscle MechanicsMuscle Mechanics Bone Growth and StrengthBone Growth and Strength Optics of the EyeOptics of the Eye Information ProcessingInformation Processing

SMP PhilosophySMP Philosophy

www.physlink.com

Feedback Requested!Feedback Requested!

What do you want to be the focus of nextWhat do you want to be the focus of next

week’s lecture?week’s lecture?A.A. The mechanics and motion of DNA The mechanics and motion of DNA

moleculesmolecules

B.B. The use of lasers to study DNA functionThe use of lasers to study DNA function

C.C. The biological relevance of my research on The biological relevance of my research on DNA mechanicsDNA mechanics

D.D. No particular preferenceNo particular preference

AcknowledgementsAcknowledgements

Saturday Morning Physics SupportSaturday Morning Physics Support Dr. M. Lois TiffanyDr. M. Lois Tiffany and other donors and other donors Dr. David Gerdes & Carol RabuckDr. David Gerdes & Carol Rabuck

Lecture PreparationLecture Preparation DemolabDemolab

• Warren Smith, Harminder Sandhu, Mark Warren Smith, Harminder Sandhu, Mark KennedyKennedy

Slide PreparationSlide Preparation• Chris Meiners Ph.D.Chris Meiners Ph.D.