Maharashtra Board Class 6 Science Chapter 8 Our Skeletal System and the Skin PDF Download

Our Skeletal System and the Skin

Can You Recall?

Which organ systems do you see in the figure alongside?

In the previous classes, we have learnt about some organ systems, their functions and their locations in our body. With the help of that, complete the following table.

The various organs are safe within the body cavity. The human skeleton is a protective shell for all the internal organs.

Can You Tell?

Sometimes when we fall while playing or have an accident, a bone in our arm or leg may get broken. This is called a fracture of the bone.

A fracture in a bone causes severe and unbearable pain and the part with the broken bone swells immediately.

Your friend meets with an accident and a bone in his leg is fractured. How will you help?

After an accident, prevent any movement of the fractured part. Immobilize it and get immediate medical help. After going to the hospital, an X-ray image is taken of the part which is swollen.

X-rays were discovered by Wilhelm Conrad Roentgen.

Teacher's Note

When you break your bone while playing, you must not move that part. Your parents will take you to the doctor. The doctor will take an X-ray picture to see where the bone is broken. This is like taking a photo of your bone from inside.

Exam Trick

Remember: Fracture = bone is broken. It causes pain and swelling. Think of it like a stick that breaks when you bend it too much.

Points to Remember

A fracture is when a bone breaks because of an accident or fall.
A broken bone causes severe pain and swelling in that part.
We need to stop the broken part from moving and get medical help quickly.
X-ray images help doctors see exactly where the bone is broken.
X-rays were discovered by Wilhelm Conrad Roentgen.

Let's Try This

Let's identify our bones.

1. Place your hand at the centre of your chest and your friend's back.

2. What is the name of the hard part you feel on placing your hand on your chest?

3. Do you feel some hard bumps on the back? What are they called?

4. What difference do you notice between the bones of the back and those of the chest?

The Human Skeletal System

All the bones in our body are not of the same shape. Every bone is different. All the bones together form a framework or skeleton. The skeleton gives a shape to the body.

All the bones of the body along with cartilage together form the skeletal system.

Bones are hard. They are not flexible. Bones are composed of two main constituents. Bone cells are biotic, while calcium carbonate, calcium phosphate, minerals and salts are the abiotic constituents of bones. Calcium imparts strength to the bones.

The system which gives a definite shape to the body, provides support and protects the delicate organs inside the body is the skeletal system.

Teacher's Note

Your skeleton is like the frame of a building. Just like the frame holds up the whole building, your skeleton holds up your whole body and keeps it standing straight.

Exam Trick

Remember: Skeleton = bones together form a frame. Calcium = makes bones strong. Think of milk as calcium - it makes your bones strong and hard like concrete in a building.

Points to Remember

The skeleton is made of all the bones in your body plus cartilage.
Every bone in your body has a different shape and size.
Bones are hard and not flexible.
Calcium makes bones strong and hard.
The skeleton gives shape and support to your whole body.

Types Of Bones

Bones of our body are classified into four types.

1. Flat bones

2. Small bones

3. Irregular bones

4. Long bones

An X-ray image shows whether a bone is broken and also the exact spot where it is broken. This helps in providing the proper treatment.

Teacher's Note

Your body has four different types of bones. Flat bones are like a plate. Long bones are like a stick in your arm and leg. Small bones are tiny like in your ear. Irregular bones have strange shapes like in your spine.

Exam Trick

Remember: Four types of bones - Flat, Small, Irregular, Long. Think of them like: Plate (flat), Rice grain (small), Odd shape (irregular), Stick (long).

Points to Remember

There are four types of bones in our body.
Flat bones look like plates and protect organs.
Long bones are in your arms and legs and help you move.
Small bones are tiny and are found in your ears.
Irregular bones have strange shapes and are in your spine.

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