Alcohol and smoking (AQA GCSE Biology Combined Science): Revision Notes
Alcohol and smoking
What are alcohol and smoking?
Drinking alcohol and smoking are lifestyle risk factors. This means they are things we choose to do that can increase our risk of getting certain non-communicable diseases.
Non-communicable diseases are illnesses that cannot be passed from person to person, like heart disease and cancer. Unlike infectious diseases, these conditions develop over time and are often linked to our lifestyle choices.
Effects of alcohol
Ethanol is the type of alcohol found in alcoholic drinks like beer, wine and spirits.
Short-term effects of alcohol
When someone drinks a lot of alcohol at one time, it can cause immediate problems:
How Alcohol Affects the Brain
These effects happen because alcohol affects how the brain works, slowing down the central nervous system and impairing normal brain function.
- Blurred vision - things look fuzzy and unclear
- Slow reactions - it takes longer to respond to things
- Lowered inhibitions - people take more risks and make poor decisions
Long-term effects of alcohol
Drinking a lot of alcohol over many months or years can cause serious damage:
- Brain damage - alcohol can permanently harm brain cells
- Liver cirrhosis - the liver becomes scarred and stops working properly
The liver is the organ that breaks down alcohol, so it gets damaged when people drink too much over time. Once liver cirrhosis develops, the damage is often irreversible.
Effects on pregnancy
When pregnant women drink alcohol, it can seriously harm the developing baby:
- Poor growth - the baby may not grow properly in the womb
- Abnormal facial features - the baby's face may not develop normally
- Learning and behaviour problems - the child may struggle at school and have difficulty controlling their behaviour
Critical Warning for Pregnancy
The more alcohol consumed, the greater the risk becomes. There is no known safe amount of alcohol during pregnancy - even small amounts can cause harm to the developing baby.
Effects of smoking
Tobacco smoke contains many different harmful substances that damage our health.
Harmful substances in cigarettes
Three Key Harmful Substances
Every cigarette contains thousands of chemicals, but these three are particularly dangerous and cause the most serious health problems.
- Nicotine - this substance is addictive, making it very hard to stop smoking
- Carbon monoxide - this poisonous gas reduces how much oxygen the blood can carry around the body
- Tar - this sticky substance contains chemicals called carcinogens that cause cancer
Health problems from smoking
Smoking causes several serious health issues:
Cardiovascular problems:
- Substances in cigarettes make blood vessels narrower
- This increases blood pressure
- Higher risk of heart attacks and strokes
How Smoking Affects Blood Flow
When someone smokes, the nicotine causes blood vessels to constrict (become narrower). At the same time, carbon monoxide reduces the oxygen-carrying capacity of blood. This means the heart has to work harder to pump oxygen around the body, leading to increased blood pressure and strain on the cardiovascular system.
Cancer risk:
- Chemicals in tar cause cancers, especially of the mouth and lungs
- These carcinogens damage cells and make them grow out of control
Effects on babies:
- Pregnant women who smoke have babies with low birth weight
- This happens because carbon monoxide reduces oxygen levels in the blood
Understanding graphs and data
Reading Health Data
When looking at data about health risks, you might see different types of relationships that help scientists understand how lifestyle choices affect our health.
Positive correlation: When one factor increases, the other also increases. For example, as alcohol consumption increases, liver disease rates also increase.
Negative correlation: When one factor increases, the other decreases.
Remember!
Key Points to Remember:
- Alcohol contains ethanol which affects the brain and can damage the liver over time
- Short-term alcohol effects include blurred vision, slow reactions, and poor decision-making
- Long-term alcohol use can cause brain damage and liver cirrhosis
- Smoking contains harmful substances like nicotine (addictive), carbon monoxide (reduces oxygen), and tar (causes cancer)
- Both alcohol and smoking during pregnancy can seriously harm developing babies
- The more you consume, the greater the health risks become - but the good news is that reducing or stopping these habits can improve your health