Lesson: Chapter 6 — Human body processes

Diseases of the respiratory system 3 of 3

Smoking

Smoking causes lung cancer, bronchitis and other diseases, and raises the risk of many more — and of death.

Carbon monoxide

It is absorbed into the blood and binds quickly to haemoglobin, leaving less room for oxygen — so the blood carries less oxygen.

Nicotine

It raises the heart rate and blood pressure for a while.

Damaged cilia

Smoke destroys the cilia, so mucus and dust collect in the airways, causing blockage and bronchitis.

Cancer

Exposure to smoke can make cells in the trachea lining grow abnormally, forming cancerous growths.

Passive smoking

People who do not smoke can suffer all of this by breathing in other people's smoke.