Page 26 - Viva ICSE Science 5 : E-book

Backbone

The backbone is also known as the vertebral column or the

spine. It consists of 33 irregularly shaped small bones called
the vertebrae (singular—vertebra). Vertebrae are placed one
above the other to make a vertebral column. These bones

make a strong framework which protects the spinal cord. The
vertebral column enables us to stand upright and maintain

balance.
Backbone

Ribcage

Ribcage or the chest bone is present in the chest region.
It consists of 24 bones, known as ribs, arranged in 12 ribs

pairs. Ribs are thin, fl at and curved bones. They form a
protective cage around the heart and the lungs called

the ribcage. The ribs are joined to the sternum in the sternum
front and to the backbone at the back. Sternum is a long
fl at bone present in the front of the chest region. Apart

from protecting the heart and the lungs, the ribcage also
provides support in respiration. Ribcage

Jawbone

Jawbone or the bone of the lower jaw is one of the 14 bones
of the facial structure. This U-shaped bone is the strongest and

the largest bone of the skull. It holds the teeth of the lower jaw. It is
Jawbone
the only movable bone of the skull and helps us to eat and speak.

Importance of Bones

Bones are an important component of the skeletal system as they provide a framework
around which the body is built. Besides providing shape to the body, bones perform
various other functions. Some reasons why bones are important to the body are as

follows.

• Protection: Bones protect the delicate internal organs of the body. For example,
skull protects brain and ribcage protects lungs and heart.

12