1What's in tobacco smoke
Tobacco smoke contains thousands of chemicals. Nicotine is an addictive stimulant. Sticky tar causes cancer. Carbon monoxide is a poisonous gas that cuts the oxygen the blood carries.
nicotinetarcarbon monoxide
Lesson 16.4 notes
Smoking, and drugs in pregnancy
What is in tobacco smoke, a smoking machine, smoking and the lungs and heart, vapes and second-hand smoke, and harm to an unborn baby.
2A smoking machine
A pump draws smoke through cotton wool and an indicator. The cotton wool turns brown with tar, the indicator shows the smoke is acidic, and the temperature rises.
taracidic
3Cilia and mucus
Cells lining the airways make sticky mucus that traps dirt and microbes, and tiny hairs, cilia, sweep it away. Smoke damages the cilia, so mucus builds up and has to be coughed up.
mucuscilia
4Lungs and heart
Smoking causes most lung cancers. It breaks down the walls of the alveoli (emphysema), so there is less surface for gas exchange. It also raises the risk of heart disease and strokes.
lung canceremphysema
5Nicotine
Nicotine reaches the brain within seconds of a puff. It makes the heart beat faster and is very addictive, which is why stopping smoking is hard. Stopping at any age improves health.
nicotineaddictive
6Vapes and second-hand smoke
Most vapes contain nicotine but no tar or carbon monoxide: less harmful than smoking, but not risk-free, and illegal to sell to under-18s. Second-hand smoke harms people nearby, especially children.
second-hand smoke
7Smoking and drinking in pregnancy
Harmful substances cross the placenta into the baby's blood. Carbon monoxide means the baby gets less oxygen, so it may be born small or early. Alcohol can cause FASD (foetal alcohol spectrum disorder).
placentaFASD
Explore: Smoking machine
Draw air, or tobacco smoke, through the machine and compare the cotton wool, the indicator and the thermometer.
Common mistake: Smokers aren't the only people harmed
Second-hand smoke, breathed in by people nearby, has the same harmful chemicals. It is especially harmful to babies and children, which is why smoking is banned indoors in public places and in cars carrying children.
Remember
- Tobacco smoke contains nicotine (an addictive stimulant), tar (causes cancer) and carbon monoxide (cuts the oxygen the blood carries).
- Smoking damages cilia and alveoli and causes lung cancer, emphysema and heart disease. Most vapes have nicotine but no tar or carbon monoxide.
- In pregnancy, carbon monoxide and alcohol cross the placenta: babies may be born small or early, and alcohol can cause FASD.
Going further at GCSE