Transcript Gravitation can not be held responsible for people falling in love

Calling 911: The Physics of
Heart and Lung Function
Seth Blumberg
University of Michigan
Physics Department / Medical School
www.umich.edu/~sblumber
Public Lectures
 Ta-You
Wu Lecture
Sir Martin Rees: Where is Cosmology Going?
Wed. Nov 12 at 4pm, East Hall Auditorium
 25th
Distinguished Faculty Lecture
Homer Neil: The CERN Large Hadron Collider
Wed. Nov 19 at 4pm, 340 West Hall
An X-ray Anniversary!
Courtesy of Perry Pernicano M.D.
From Cancer to Medical School
Cancer changed
my life, but it did
nothing to my
love of physics!
Lung
www.louisville.edu/medschool/physiology/
http://www.electrosols.com
Lung Function
http://www.jamesline.com
Quiz Time!
The surface area of the interior of an adult
lung is closest to:
A.
B.
C.
D.
1 square meter
5 square meters
20 square meters
100 square meters
Hint: There are about 300 million alveoli (each
about .1mm in radius)
Weight of Air Demo
M1
Weight
M1
M2
M2
Buoyancy
Vacuum
Pressure Varies with Height
p  p0 e
Mgy

RT
Mount Everest
Denver
www.npl.co.uk
Atmospheric Pressure &
Tuberculosis
www.adventures.com
www.electrosols.com
Atmospheric Pressure
ww2010.atmos.uiuc.edu
Punctured Chest = Pneumothorax
From Human Physiology Rhoades & pflanzer, 2nd edition
Surface Tension
bio.bio.rpi.edu/Parsons
http://home.earthlink.net
Quiz Time!
What is going to happen?
A.
B.
C.
D.
The bubbles will become equal size.
The large bubble will collapse into the smaller
bubble
The small bubble will collapse into the larger
bubble
The bubble sizes will oscillate back and forth
Surface Tension of a Bubble
Key Point:
Smaller bubbles have
a larger pressure
differential
bio.bio.rpi.edu/Parsons
Lung
www.louisville.edu/medschool/physiology/
http://www.electrosols.com
The Physics of Emphysema
education.vetmed.vt.edu

ww2.mcgill.ca/pathology
Surface Tension plays a major role in the life of 3
million Americans!
Surfactants Decrease Surface
Tension
bio.bio.rpi.edu/Parsons

Lung Surfactants play an important role in
Premature Birth
Heart
Gravitation can not be
held responsible for people
falling in love
- Albert Einstein
sprott.physics.wisc.edu/
Heart
http://www.cts.usc.edu/
MRI 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
Blood Flow
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.
www.colby.edu/biology
Poiseuille Flow

Resistance is highly sensitive to diameter of
4
vessels.
1
r
Q
8 L
p
R
r4
Quiz Time!
R1
If I add a resistor to the circuit, the current
from the battery will?
A.
B.
C.
D.
Decrease
Increase
It depends on how I attach the resistor
None of the above - The battery will explode
Series & Parallel Resistance
R1
R2
Req = R1 + R2
R1
R2
1/Req = 1/R1 + 1/R2
Fetal 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 Circulation
http://bio.bio.rpi.edu/Parsons
Resistance plays an important role in a baby’s first
breath!
Pressure Waves cause aneurysms
Quiz Time!
Fighter Pilot g-suits are most
similar to a mechanism found in:
A.
Giraffes
B.
Fish
C.
Birds
D.
None of the above. Gsuits are for looks only
microgravity.grc.nasa.gov
Bernoulli’s Principle
1 2
Pext   v   gh
2
 constant
www.artsafaris.co.ke
Other Physics in Medicine
 Electrophysiology
 Diffusion
 Muscle
Mechanics
 Bone Growth and Strength
 Optics of the Eye
 Information Processing
SMP Philosophy
www.physlink.com
Feedback Requested!
What do you want to be the focus of next
week’s lecture?
A.
B.
C.
D.
The mechanics and motion of DNA
molecules
The use of lasers to study DNA function
The biological relevance of my research on
DNA mechanics
No particular preference
Acknowledgements
 Saturday


Dr. M. Lois Tiffany and other donors
Dr. David Gerdes & Carol Rabuck
 Lecture


Morning Physics Support
Preparation
Demolab
• Warren Smith, Harminder Sandhu, Mark
Kennedy
Slide Preparation
• Chris Meiners Ph.D.