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 fine, hair-like fi 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 The burning of tobacco produces a residue known as ficult. r, tar which consists of small, thick, sticky particles. Over time, as smoke repeat- r 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) pulmonary disease (COPD ) refers to a group of diseases that make it more diffi to breathe (Figure 9.3). Most smokers who develop COPD have a ficult combination of chronic bronchitis and emphysema. tar r a thick, sticky substance produced by burning tobacco can disrupt the respiratory systems of smokers chronic obstructive pulmonary p disease (COPD) term for a group of diseases that cause diffi ficulty breathing includes chronic bronchitis and emphysema Right lung g Trachea Bronchus Normal bronchiole Narrowed bronchiole Alveolus Normal COPD Asthma Chronic Bronchitis Emphysema COOOPD OP OPD CO O COPD Chronic obstructive pulmonary disease (COPD) clogs the bronchioles and damages the lungs, making it more diffi cult to breathe. Figure 9.3