Richard Heath (slide 19) and Tadge Bredwell (slide 18) (Video Script pgs 45-46) died from emphysema, severely short of breath (see slides p, q). Their shortness of breath came from a combination of the factors discussed above: 1) mechanical nerve receptors which sensed their increased work of breathing during exhalation because of narrowed airways which obstructed expiratory airflow, 2) mechanical nerve receptors which sensed their increased work of breathing during inhalation, trying to stack more air into already hyperinflated lungs and 3), chemical nerve receptors which sensed reduced levels of blood oxygen and increased levels of blood carbon dioxide. These abnormalities in blood oxygen and carbon dioxide occurred because their breathing failed and this was a direct result of their smoking! Can you imagine how they suffered?

4. Demonstration: The effect of smoking on the heart rate.
Recruit a cigarette smoker, take their pulse just before and after smoking a cigarette and record the results.

Result: The pulse rate increases after smoking just one cigarette.
Why? The pulse rate is a measure of the heart rate and nicotine is a cardiac stimulant which makes the heart beat faster. Nicotine from inhaled smoke is absorbed into the blood stream, reaches the heart within seconds and drives the heart to beat faster.

Significance: A constantly elevated heart rate from continued smoking places an extra strain on the heart and increases the hearts requirement for oxygen. (To make matters worse, carbon monoxide in tobacco smoke enters the blood stream, displaces oxygen in the blood and reduces the supply of oxygen to body tissues including the heart.) So with smoking, your heart needs more oxygen but gets less oxygen. Double jeopardy!

5. Demonstration: To determine the level of exhaled carbon monoxide in different subjects.
Exhaled carbon monoxide reflects blood levels of carbon monoxide. Using a carbon monoxide gas meter, (available from Micro-Direct, Inc. at 1-800-588-3381) determine the level of carbon monoxide in the exhaled breath of a) heavy smokers (greater than twenty cigarettes/day), b) lighter smokers (5-10 cigarettes/day), c) non-smokers living with heavy smokers (i.e. heavily exposed daily to second hand smoke in the home), and d) non-smokers not exposed to second hand smoke.
What are your findings? Display them on a graph. What is the significance of your findings?
NOTE: Only choose subjects who smoked or were closely exposed to indoor smoke within a few hours of your measurements since carbon monoxide levels decrease significantly within eight hours of last exposure.

See CD-ROM-1 (Main Menu) for interactive visualizations and simulations.