Smoking has a diverse effect on respiration and gas exchange. Here we note its short-term effects, and consider the possible long-term effects in the corresponding article.
1. Nicotine causes a narrowing of small bronchioles, resulting in increased resistance to air flow in the airways.
2. Nicotine paralyzes the cilia, removing dust particles and bacteria from the airways. The accumulation of foreign material makes it difficult for air to pass through these paths.
3. Smoke acts as an irritant ; as a result, the goblet cells of the epithelium secrete more mucus, which also increases the resistance to air flow.
In asthma, difficulty breathing is caused by a spasm of smooth muscle in the walls of the bronchioles. Due to muscle contraction, the lumen of the bronchioles narrows, and sometimes even closes completely. In this case, exhalation is more difficult than inhalation, because the pressure of the air leaving the lungs compresses the tubes even more.
During an asthmatic attack, breathing is accompanied by a characteristic whistling sound or wheezing, especially strong when exhaling. Another unpleasant symptom is excessive accumulation of sputum, thick and difficult to separate when coughing. It accumulates in the bronchioles and makes breathing more difficult. The bacteria that got into it can multiply in sputum, and then asthma is complicated by bronchitis. Edema of the bronchial mucosa also makes breathing difficult.
The basis of asthma is an increased sensitivity of the body to various, for healthy people, usually harmless, substances – allergens. Most often, asthma is caused by allergens such as pollen, household dust (which may contain, for example, the smallest mites or mold spores), any food components, or feather with pillows. An emotional upset can also provoke an attack.
Asthma attacks can also occur in connection with cooling, physical exertion, or as a result of smoking. A very disturbing phenomenon – the increasing frequency of asthma in children in cities – is believed to be due to the ever-increasing pollution of urban air from car exhausts. In the exhaust gases there are some substances that can cause asthma attacks, so in industrialized countries the legislation on this subject has recently been toughened up. However, asthma is a complex problem and new research is needed to establish who is most at risk and why. Anti-inflammatory drugs can provide some benefits in treating asthma.