Aseel Samaro Exploring Human Skeleton. There are 206 bones in the human skeleton. which one is the...

Aseel Samaro

Exploring Human Skeleton

There are 206 bones in the human skeleton.

which one is the smallest?which one is the largest?

Each one contains calcium to make it strong.

Human skeleton

Bones make up the human skeleton. Without your skeleton you would flop!

The main bones of the human skeleton

Bones must be strong to support you.

Most of the bones (approximately 70 per cent) is made up of hard minerals, such as calcium.

The outside of a bone is smooth and hard to provide support.

Inside this hard outer layer lies spongy, porous material This spongy layer allows your bones to bend slightly.

It also makes your bones lighter than if they were completely solid.

At the centre of a bone is a softer substance called marrow.

Investigating the structure of the bone

Some bones are long and narrow, such as those in your arms.

Some bones are shorter, such as those in your feet.

Other bones are flat and wide, such as the scapula (shoulder blade).

Each bone is adapted to suit its function.For example, the foot contains many small bones to allow flexibility.

Comparing bones

Femur

Scapula

For each of the examples below, describe how the bone shape or structure is well adapted for its function in the body:

Femur (thigh bone) long and wide: gives strength to support the body weight

Bones of the hand Many small bones with joints: allows the hand to bend in different directions

Ribs curved: to protect lungs inside the chest cavity

Q.7 Page 11

The structure of bone in bird has perfectly adapted to the function of flying

Many bones in birds are hollow. They are full of air

This makes them lighter and, therefore, less energy is needed for them to fly

What feature of bird’s bone help them to fly ?

The human skeleton has four main roles:Supports the bodyProtects the organsAllows movementProduces blood cells.

Without a skeleton you would not be able to sit, stand or hold yourself up.

Analysing the skeleton

The ribs are curved bones, forming a cavity inside the ribcage. The lungs are positioned inside the ribcage.

The many joints in your skeleton allow you to move. For example, the joint at the knee allows your leg to bend. Without joints, your skeleton would be rigid.

Your ears and the end of your nose do not contain bone. Instead, these body parts are given their shape by cartilage.

Cartilage is softer than bone and does not contain blood vessels or nerve cells.

Did you know ?

Bone

Explain which organ each part of the skeleton protects:

RibsCranium

Describe three parts of the skeleton where joints are important.

Bone marrow is in the centre of large bones.

It is here where blood cells are made.

There are three types of blood cells :Red blood cells carrying oxygenWhite blood cellsPlatelets.

Patients with some medical conditions cannot make their own healthy blood cells.

If a bone marrow transplant is carried out the patient may then make healthy blood cells again.

The importance of bone marrow

Transplant: transferring living tissue from one person to another

What is meant by transplant?

Your skeleton has many symmetrical features.

This helps you to balance and co-ordinate movements.

Skeletons are usually made in similar proportions. For example, if you stretch your arms as wide as you can and measure their arm span, this will probably be similar to your height.

At an archaeological dig or a crime scene, only a few bones may be found.

Yet scientists can predict the height of a person using only the length of:The femurHumerusthe smaller bones in the arms and legs.

Using Bone Measurements

The calculation used to estimate height from the length of the femur is:

height (m) = (length of femur (m) × 2.6) + 65

A femur, 0.35 m in length, is found during a police investigation. Estimate the height of the victim. (Remember units). Estimate the arm span of the same victim.

Using Bone Measurements

Calculation is not always accurate in people between 12 and 18 years of age. WHY ??

Thank you