2.47 Understand the biological consequences of smoking in relation to the lungs and the circulatory system, including coronary heart disease

• Smoking causes tar to build up in your lungs, which can lead to cancerous mutations and the formation of tumors
• It destroys the cillia that line the trachea (whose job is to stop unwanted particles entering the lungs)
• It causes the build up of mucus (can cause smoker's cough) which could lead to infections in the trachea and bronchi; bronchitis
• Hardens the arteries, which makes blood flow increasingly difficult and puts strain on the heart, leading to coronary heart disease.

Figure 1