This document discusses the harmful effects of three substances found in tobacco smoke - nicotine, tar, and carbon monoxide. Nicotine is addictive and raises blood pressure, while tar damages lung tissue and DNA, increasing cancer risks. Carbon monoxide reduces the blood's ability to carry oxygen throughout the body. Long-term smoking can lead to diseases like bronchitis and emphysema and damage the lungs' ability to exchange gases.

1. How does it affect a human’s body?

2. Tobacco
leaves
Cigarettes Cigars Pipes
Water pipes
(shisha)
smoking and lung cancer deaths
0
20
40
60
80
100
non-smokers cigars only pipes only mixed cigarettes
deathsper100000from
lungcancerinmenaged
40-79

3.  There are about 4,000 harmful substances in
tobacco smoke. We will study only 3.
 Nicotine
 Tar
 Carbon monoxide

4.  It is an addictive drug.
 It raises blood pressure and
increases the heart rate.
 Nicotine also increases the
chance of blood clot
formation. Blood clots formed
in the coronary arteries
prevent oxygen and glucose
from reaching the heart muscle
tissue. The smoker experiences
a heart attack. ¼ of the deaths
from heart diseases is due to
smoking.

5.  It is a black substance that can be
seen clearly in smokers’ lungs.
 It is deposited on the alveoli
walls which slows down the rate
of diffusion.
 It damages the DNA which
results in uncontrollable cell
division creating tumours
(cancer cells).
 These cells take place of the
normal cells but do not perform
their functions. They also use up
nutrients to support their quick
growth.

6. Non-smoker’s
lung
Smoker’s lung

8. Tar stops cilia
of ciliated cells
from beating.
Tar increases
mucus
secretions.
Tar damages
the DNA causing
cancerous cells
to form and
multiply.

9.  The result of these 2 actions is that dust and
bacteria are trapped in the lungs but are not swept
out of the lungs by the cilia. The accumulation of
bacteria causes a disease called bronchitis (the
inflammation of the bronchi).

10.  This condition worsens till a person’s lungs are
not able to exchange gases efficiently to help him
survive. This is emphysema.
 The loss of the large surface area cannot be
repaired, as a way to increase the rate of oxygen
diffusion the patient has to live with a pure
oxygen supply to breathe.

11.  This toxic gas results from the incomplete
combustion causing carbon to bind to one oxygen
instead of two.
 CO binds to haemoglobin in the red blood cells so
strongly that haemoglobin can no longer carry
oxygen. Less oxygen can be carried to all body
cells; another reason to why smokers cannot be
good athletes.
 Carbon monoxide also increases chances of blood
clotting.

12.  Research different methods that can be used to
quit smoking.
 Write a one-page article about the benefits of
quitting smoking and different methods used to
help smokers quit.
 Work in pairs, & remember
to add your sources.
 Deadline: