Life expectancy Flashcards
(16 cards)
What is life expectancy?
The average number of years a person is expected to live.
In the past, how was the life expectancy?
People only lived 30-40 years.
Many died from infections or bad food.
Currently, how is the life expectancy?
People may live upto 90 years.
This is because there are few deadly diseases due to advances in medicine and cleaner living.
What are the reasons for higher life expectancy?
Better hygiene;
Better diet;
Food hygiene;
Immunisation with the help of vaccines;
Medicine and antibiotics.
How has better hygiene contributed to higher life expectancy?
By stopping the spread of germs.
Ex: having showers; washing hands.
How does better diet contribute to a higher life expectancy?
People who have a balanced diet are healthier than those who don’t.
Healthier and strong individuals have more active immune systems which can fight off diease-causing microorganisms.
What is food hygiene?
Most microorganisms in food and drink are bacteria, which can food to spoil or go bad.
Food hygiene prevents harmful microorganisms from being transmitted in food, preserving food and reducing its rate of spoilage.
Ways to maintain good food hygiene:
-Cook food properly (TO KILL MICROORGANISMS)
-Cooked and raw meat must be stored separately to avoid bacteria from raw meat contaminating the cooked meat.
-Food which have been previously frozen and thawed must be cooked straight away (BC RATE OF BACTERIAL GROWTH IS HIGHER THAN FRESH FOODS)
-Food should not be left in open air as bacteria could land on the food from air or contaminated by an insect.
Olden methods of food preservation:
Salting: Covering food with salt or soaked in salt water. High salt concentrations stop multiplying bacteria.
Pickling in vinegar: Vinegar provides an acidic pH which inactivates microorganisms.
New methods of preservation:
Canning: Food is packed in cans, heated in high temperatures, sealed, and then re-heated again at high temperatures. This kills the bacteria and their spores.
Drying: Food is dried by blowing hot air through it, removing water so bacteria can’t digest and absorb food.
Ultra heat treatment: Super heated steam is blown through the food for 2 secs, killing bacteria and spores.
How does immunisation with vaccines help life expectancy:
Using vaccines can prevent people from developing certain diseases.
Before modern medicine, infections were treated by:
Herbal remedies: chewing on willow bark helped reduce pain as it has a chemical similar to aspirin.
Honey, mud, and animal fat used on wounds.
Bloodletting: used leeches to cut the skin to let out bad blood.
Why is modern medicine and antibiotics essential for the increase in life expectancy over time?
Because it was easier to treat infections that were once considered life-threatening.
What are pathogens?
Microorganisms that cause disease.
Explain features of an infectious disease:
-Caused by pathogens.
-Transmissible (transferred from an infected organism to an uninfected organism)
-Ex: flu, Covid-19, Malaria, Measles, Chicken pox.
Explain features of a non-infectious disease:
-Caused by factors like genetics, malnutrition, environment, lifestyle.
-Not transmissible.
-Ex: diabetes, asthma, heart disease, cancer.
