Different kinds of joints

•HWHW= Give a = Give a description of fixed, description of fixed, slightly moveable and slightly moveable and freely moveable joints freely moveable joints and their main and their main function.function.

•Make a list of the Make a list of the different types of different types of freely moveable joints freely moveable joints (e.g. hinge joint) and (e.g. hinge joint) and give an example. give an example.

Learning objectives

• What is a joint and what function does it perform.

• Learn about the various types of joints found in the human body.

• Discover the damage that can be caused at joints.

Introduction

• Your skeleton is made up of 206 bones.

• Joints are where two, or more, bones meet.

• They are divided up into three types depending on how freely the bones can move.

• If we did not have joints no movement would occur.

Task

1. What is a joint?

2. Why do we have joints?

http://www.bbc.co.uk/schools/gcsebitesize/pe/anatomy

Fixed or immovable joints

• Bone’s at an immovable joint can’t move at all.

• They either interlock or overlap.• A good example is the joints

between the plates of the cranium.

• Fused joints in the sacrum are another good example.

• We have this type of joint in areas requiring great strength.

Task

1. What are the four functions of the skeleton and briefly describe how it does these?

This ensures that our vital organs are kept safe from bumps and knocks

Supports

Produces

This allows us to contract and relax at each joint in the body

Slightly movable joints• These bones at a slightly movable joint

can move only a little.• They are held together by strong white

cords or straps called ‘ligaments’ and joined by cartilage.

• Cartilage is a gristly cushion and stops the bone from knocking together.

• Joints between most of your vertebrae are slightly moveable.

• The pads of cartilage between them act as a shock absorber so the bones won’t jar when you run or jump.

Task

1. Go to: http://www.bbc.co.uk/science/humanbody/body/interactives/3djigsaw_02/index.shtml?skeleton

See if you can place all ten bones in their correct locations. Use the hint button to get a description of where it can be found.

Freely moveable joints

• Outer sleeve is called the joint capsule.– It holds bones together & protects joint.– It is an extension of the skin or

periosteum that covers the bone.• A synovial membrane.

– Lines the capsule and oozes a slippery liquid called synovial fluid.

• A joint cavity.– A small gap between the bones.– Filled with synovial fluid.– Lubricates the joint so the joint moves

more freely.• A covering of smooth slippery cartilage at the end

of the bones.– Stops the bones knocking together.

• Ligaments which hold the bones together.– Freely moveable joints are also called

synovial joints.

Knee joint from the side

Task

1. In your own words, write a description of the following synovial joints and get one example of each in the body.

• Gliding –

• Hinge –

• Pivot –

• Ball and socket –

• Ellipsoid –

http://www.bbc.co.uk/schools/gcsebitesize/pe/anatomy/jointsrev4.shtmlUse slides 15 onwards for help

Joints and injury• Impact

– Severe contact, e.g. falling from a horse onto your shoulder, could cause dislocation. This is where a bone is pulled out of its normal position. Causing tearing of the ligaments (sprain) and tendons.

• Wear and tear– Exercise of a joint or unusual

use of it could cause cartilage to be worn away. Joint could swell causing it to stiffen.in older people it could cause arthritis. This makes the joint stiff and swollen.

Task

1. Give your own example of an impact injury

2. And a sporting example of wear and tear

Task

1. What parts make a synovial joint a) strong and stable b) help it move easily.