Copyright Goodheart-Willcox Co., Inc.
Chapter 9 Tobacco 261
The Respiratory System
The respiratory system’s primary function is to enable breathing. First,
the nose takes in air, which then travels down the respiratory tract. The nose,
bronchial tubes, and lungs are all lined with tissue containing fi ne, hair-like
projections called cilia. The cilia trap and move foreign particles out of the
respiratory tract. Air then travels into tubes (bronchi) and into the lungs.
When a person smokes, damage is done to the respiratory system that makes
breathing more diffi cult. The burning of tobacco produces a residue known as
tar, which consists of small, thick, sticky particles. Over time, as smoke repeat-
edly passes through the bronchial tubes, tar builds up in the lungs. Tar disrupts
the ability of the cilia to effectively clear the lungs of foreign particles.
Smoking-related damage to the lungs also contributes to the develop-
ment of chronic respiratory diseases and can trigger asthma attacks.
Chronic Obstructive Pulmonary Disease (COPD). Chronic obstructive
pulmonary disease (COPD) refers to a group of diseases that make it more
diffi cult to breathe (Figure 9.3). Most smokers who develop COPD have a
combination of chronic bronchitis and emphysema.
tar
a thick, sticky substance
produced by burning tobacco;
can disrupt the respiratory
systems of smokers
chronic obstructive
pulmonary disease
(COPD)
term for a group of diseases
that cause diffi culty
breathing; includes chronic
bronchitis and emphysema
Right lung
Trachea
Bronchus
Normal
bronchiole
Narrowed
bronchiole
Alveolus
Normal COPD
Asthma
Chronic
Bronchitis
Emphysema
COPD COPD
Chronic obstructive
pulmonary disease (COPD)
clogs the bronchioles and
damages the lungs, making it
more diffi cult to breathe.
Figure 9.3
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