Maharashtra Board Class 8 Science Chapter 2 Health and Diseases PDF Download

Health And Diseases

2.1 Checking Fever

Have you ever taken leave from school due to sickness?

What happens exactly when we become sick?

Sometimes, we feel good even without taking any medicines and sometimes we need to consult doctor and take regular medicines in sickness. Why is it so?

Health

Health is a state of complete physical, mental and social well-beingness and not merely the absence of any disease.

Teacher's Note

Health means our body, mind and heart are all healthy. When your parents take care of you and you play games, you are staying healthy like a healthy mango tree that bears good fruit.

Exam Trick

Remember: Health = Physical + Mental + Social well-being. It is NOT just no disease. This is the main trick in exams.

Points to Remember

Health is a complete state of physical, mental and social well-beingness.
Health is much more than just not having a disease.
A healthy person can work well and be happy.
We need to take care of our body, mind and feelings.

What Is Disease?

Condition of disturbances in physiological or psychological processes of body is called as disease. Each disease has its own specific symptoms.

Types Of Diseases

You must have heard the names of various diseases like diabetes, common cold, asthma, Down's syndrome, heart disease, etc. Reasons and symptoms of all these diseases are different. To bring coordination in scientific study of diseases, diseases are classified as follows.

Teacher's Note

Diseases are of two types - those you can catch from others (infectious) and those you cannot (non-infectious). Like how you can catch cold from a friend but cannot catch diabetes from them.

Exam Trick

Remember: Infectious = spreads from person to person. Non-infectious = stays with one person only. Think of cold as infectious (spreads) and diabetes as non-infectious (does not spread).

Points to Remember

Diseases can last for short time (acute) or long time (chronic).
Hereditary diseases are passed from parents to children.
Acquired diseases are caught from environment or other people.
Infectious diseases spread from sick to healthy people.
Non-infectious diseases do not spread to other people.

2.2 Infection Through Sputum

When a person coughs or sneezes, small droplets come out from mouth. In this area small droplets are vaporised into fine mist. Mist remains in the air for several minutes to few hours. Large droplets settle on the ground within few seconds.

Teacher's Note

When you cough without covering your mouth, droplets fly in the air and can make other people sick. This is why we should cover our mouth when we cough - just like we do in schools to keep our friends healthy.

Exam Trick

Remember: Small droplets stay in air (mist floats), large droplets fall down fast. This is why we cover our mouth - to stop small droplets from flying.

Points to Remember

When sick person coughs, droplets come out from mouth and nose.
Small droplets float in air as a mist for hours.
Large droplets fall to ground in few seconds.
We can catch disease from floating droplets by breathing.
Covering mouth while coughing stops disease spread.

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