Page 27 - FOUNDATIONS FOR LIFE; EXPLORING GOD’S UNIVERSE

Science Y6 – Marvellous Me – lesson 4 – information on bones and muscles

About Bones and Muscles

Fascinating Facts

• A baby has 300 bones at birth.
• An adult has 206 bones.
• One half of your bones are in your hands and feet.
• It takes 15 muscles to smile...43 muscles to frown!
• Every day your muscles do enough work to lift 24,000 pounds onto a 4 foot high shelf.
• There are 656 muscles in the human body.
• 25% of your bones are water.

Background Information

The skeleton is the body's framework. Without it we could not stand up straight. We would simply flop around like jelly. Not all animals
have bones. Worms don't. Other animals such as lobsters wear a protective shield on the outside of their bodies; this is called an
exoskeleton.

A baby starts out with 300 bones when it is first born. Some of those bones later fuse together. An adult skeleton has 206 bones. About
half of all of the bones are found in the hands and feet.

When you are born, your bones are soft. They are made of a rubbery substance called cartilage. (Your nose is made of cartilage.) Soon
after you were born, your bones started to harden.

Types of Bones

Long bones are long and skinny. Some examples would be the bones in your arms, legs, and fingers.

Short bones are short and chunky. These are the bones found in your ankles or wrists.

Flat bones include your ribs and shoulder blades. They are the plate-like bones.

Irregular bones are the bones that don't fit in the three categories listed above. They are the odd shaped bones such as the bones of the
vertebrate and the bones inside your ear. Bones are very much alive. 30% of the bone is living tissue. 25% of the bone is made of water.
The red blood cells in your body is actually made by your bones in a special soft tissue called marrow.

Bones are very strong for their weight. The centres of the long bones in your body are hollow. This shape provides lightness and a place
for blood marrow, which produces the red blood cells your body needs.

The bones in your body are connected with different types of joints. They allow your body to move in several different ways.

Muscles

Connected to your bones are 656 muscles. Muscles are responsible for your body's every move. Muscles keep your tongue moving, your
heart pounding, and your lungs pumping. Muscles keep your throat clear and your food moving along. Muscles are more than movers. In the
process of all their work, they make much of the heat that keeps us warm. The average person's muscles do daily work amounting to
loading 24,000 pounds onto a four-foot-high shelf.

Muscles control all of the movements in our body with one simple action . A muscle can make itself shorter, or contract. When it isn't
contracted, it is relaxed.

Scientists know that the brain sends a signal through the nerves that tells the muscle to move in a certain way. How the muscles get the
correct message from the brain so quickly is still somewhat of a mystery.

Muscles work in teams. Every set of muscles has an opposite set of muscles so each movement can be reversed.

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