Animals including Humans

Year 3Lesson 5

LI: To understand the function of muscles and joints

What muscles do you know in the human body?

Why do we need muscles?

How do muscles work?• Muscle contraction as an active process and

relaxation as being passive and that muscles work in pairs.

Tendons, Ligaments and Cartilage• Tendons - connective tissue which attaches muscle to bone. When a

muscle contracts to move a joint, it is the tendon which pulls on the bone. • Ligaments - strong bands which connect bone to bone at the joint. • Cartilage - soft cushioning substance which covers the ends of the bones.

It reduces the rubbing of bone on bone.

Different types of joints

Where the bones meet, we have joints. 1. Hinge joints - found at the elbow and at the

knee and allow movement in one direction.2. Ball and socket joints - found at the shoulder

and at the hip and allow movement in three directions.

3. Gliding - found at the wrist between the hand and arm.

4. Saddle - a flexible joint found in the thumb.

Creating an arm

1. Cut 2 pieces of card to represent the bone.2. To create the elbow joint, join the bone using a split pin (be

careful when doing this!)3. Cut 2 pieces of string which are 10cm long. These will be the

muscles.4. Pull the bones into alignment.5. Attach the right hand piece of string above and below the

split-pin joint.6. The left hand muscle needs to be relaxed when in this

position so needs to be attached lower than the right hand muscle.

ModelArm Straight Arm Bent

Set of instructions

• Write a list of instructions about what happens when you decide to bend your arm.

Plenary

• What would happen if we did not use our muscles?