Page 38 - Active Science 5 Ebook and Activity

1. Voluntary Muscles: These are the muscles which are under our control. Muscles
attached to the skeleton of the body are voluntary muscles. These are also called as

skeletal muscles. For example under, a muscles in the arms and legs are voluntary
muscles. If we look at them under a microscope, these seem to have bands or stripes.
Therefore, they are also known as striated or striped muscles.

2. Involuntary Muscles: Those muscles which work automatically and are not under
our direct control are called involuntary muscles. They are not striated. For example,

muscles of digestive system and cardiac muscles present in heart are involuntary
muscles. These work throughout our life without stopping or getting tired.

Factual Study
Biceps Cardiac The skeleton forms the basic
Muscle framework for all animals.

The shape of the skeleton
also decides the shape of the

Triceps animal.

Activity 3.3

Divide the class bulletin board into two halves with the headings – voluntary actions and

involuntary actions. Divide the class into groups and give them chits with voluntary and
involuntary actions written on them. Each group has to identify the action and pin them up on
the board in the appropriate column.

Let’s Recapitulate

Fill in the blanks using the words from the box.
femur humerus tendons 22 206 600 12 33 hinge gliding

1. The ribcage is made up of ______________ pairs of ribs.
2. There are more than ______________ muscles in our body.

3. The skull has ______________ bones.
4. There are ______________ bones in an adult human body.

5. The vertebral column is made up of ______________ small bones.
6. ______________ joint is found in the wrists and ankles.

7. ______________ joint is found in elbows and knees.
8. Muscles are attached to the bones with the help of ______________.

9. The thigh bone in the leg is called ______________.
10. The long bone in the arm is called the ______________.

38 Active Science-5