Page 230 - DK Children's Encyclopedia

Skeleton SEE ALSO

▸ ▸ Brain p.45
▸ ▸ Heart p.128
All the bones in the human body fit together in the ▸ ▸ Human body
skeleton. They make up the shape of the human body. p.130
The skeleton forms a protective cage around the soft, ▸ ▸ Lungs p.149

inner organs like the lungs and the heart. ▸ ▸ Muscles p.173

Skull
The skull protects the
Our bones delicate brain inside. The hinge
joint lets the
The skeleton is made up arm move up
of 206 bones. The Ball and and down.
bones are moved socket joint
by muscles. Ball and socket
joints in the
shoulder and hip
allow a swivel
Ribcage movement.

Humerus Ulna Hinge joint

Radius Joints
Saddle joint Joints are the places where one bone
A saddle joint joins another to allow movement. They
allows the Pelvis Spine
thumb to move The spine is made let our bones move side to side, up and
in a circle. up of 24 bones down, or in circles. Joints have fluid in
called vertebrae.
them to help make movement smooth.

Femur Inside bones
The outer layer of bones
is made from a strong
The ends of substance called calcium.
bones are harder Inside is the bone marrow,
at the joints. which supplies blood cells
to the rest of the body. Spongy bone

Bone marrow

Bone is Tibia Types of bone
stronger There are two kinds of Compact bone
than wood, bone inside each bone.
Hard, compact bone gives
concrete, the bone strength and
or steel. protection. Spongy bone is Blood
full of little holes that make
the bone lighter.

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