Question

Briefly answer the question posed in a health education class: "How does smoking affect my lungs? Why does it increase my risk of developing COPD?" Again, full credit if in your own words. The book is an excellent resource about this, but you need to be able to explain it to a lay person!

Answer 1

ANSWER:

Chronic Obstructive Pulmonary Disease ( COPD) is a broader term used for chronic lung diseases. The main two COPD conditions are - Chronic bronchitis and Emphysema

Chronic bronchitis is a condition in which the bronchioles get inflamed resulting in increased mucus production and narrowing of the airway thus restricting airflow.

Emphysema is a condition in which the alveola or the air-sac gets damaged causing shortness of breath or  breathing difficulties.

Before understanding how smoking affects the lung and increases the risk for COPD, we need to first understand the normal mechanism of the lungs and the gas exchange.  

When we inhale, air moves into trachea also called as the windpipe and then the trachea seperates into two tubes called bronchi. The bronchi further divides into several branches called bronchioles . At the end of each bronchioles there is tiny sac-like structure called the alveoli. This alveoli expands and recoil due to its elastic-like properties as the air moves in and out. The walls of the alveoli have small blood vessels called capillaries. During gas exchange, as the alveoli expands and recoils the oxygen moves from alveoli into the capillaries and carbon dioxide from capillaries into the aveoli. So, this( alveoli) is the place where gas exchange occur. This is the normal mechanism.

However, when an individual smokes there will be certain changes in the normal mechanism.

About 80-90% of all the COPD cases are due to smoking cigarettes. When an individual smokes, more than 7000 harmful chemicals are produced or created. This smoke thus can act like an irritant because it has harmful chemicals in it. Prolonged smoking can either irritate the airway causing increased mucus production due to inflammation of the bronchi ( the bronchi gets swollened due to prolonged contact with the irritants ) or damage the air sacs ( alveoli loses its elastic-like properties) or the alveoli. The inflammed bronchi narrows the airway coupled with the mucus produced disturbs the airflow. The damage to the alveoli( air-sac) compromises the exchange of gas. This causes severe breathing difficulties. Smoking can also cause exacerbation of COPD.

This is how the smoking affects the lung and increases the risk for COPD.