© Boardworks Ltd 20061 of 37 IB Sports, exercise and health science Sub-topics Anatomy The...

© Boardworks Ltd 20061 of 37

Sports, exercise and health science

IB

Sub-topics

Anatomy

The International School of Bangkok

Joints, Tendons and Ligaments

Topic 1Anatomy

1. The Skeletal System

2. The Muscular System


Connective tissues

Connective tissues are vital to the functioning of joints. There are 3 types of connective tissue:

Ligaments are tough, elastic fibres that link bones to bones.

Tendons connect muscles to bones.

Cartilage prevents the ends of bones rubbing together at

joints. Its slippery surface also helps to lubricate the joint.


Tendons and ligaments

Ligaments and tendons are strengthened by training.

Ligaments are responsible for holding joints together. They prevent bones moving out of position during the stresses of physical activity.

If they are pulled or twisted too far by extremephysical movements, ligaments can tear andthe joint may dislocate.

Tendons anchor muscles to bones, allowing the muscles to move the skeleton. Tendons are not very elastic –

if they were, then the force produced by muscles would be absorbed instead of creating movement.

Tendons can also be torn if subjected to too much force.


Tendons and ligaments


Joint movement – what are joints?

A joint occurs where two or more bones articulate.

Without joints, our bodies would not be able to move.

Joints, along with the skeleton and muscular system, are responsible for the huge range of movement that the human body can produce.

There are several different types of joint, each producing different types and amounts of movement.


Different types of joint

There are 3 different types of joint:

1. Fibrous (or fixed) joints

3. Synovial (or movable joints)

2. Cartilaginous (or slightly movable) joints)


1. Fixed or immovable joints

There are fewer than 10 immovable joints in the body.

They are sometimes called fibrous joints because the bones are held together by tough fibres.

Immovable joints can be found in the skull and pelvis, where several bones have fused together to form a rigid structure.


2. Slightly movable joints

Slightly movable joints are sometimes called cartilaginous joints.

The bones are separated by a cushion of cartilage. The joints between the vertebrae in the spine are cartilaginous joints.

The bones can move a little bit, but ligaments stop them moving too far. This is why we can bend, straighten and rotate through the back, but not too far.

bone

ligaments

cartilage

bone


3. Freely movable or synovial joints

90% of the joints in the body are synovial joints. They are freely movable.

Synovial joints contain synovial fluid which is retained inside a pocket called the synovial membrane. This lubricates or ‘oils’ the joint.

All the moving parts are held together by ligaments.

These are highly mobile joints, like the shoulder and knee.

Synovial fluid

Knee

Synovial membrane



IB

Sub-topics

Anatomy

In Summary…•Fibrous (fixed joint) is….

•Immoveable- a joint between 2 joints that doesn’t move…

•Example- The Skull

• A Cartilaginous joint is….

•Slightly moveable- which is connected tightly by cartilage.

•Example- The spinal column

•A Synovial joint is….

•Freely moveable joint

•Example- Knee Joint

Topic 1Anatomy





IB

Sub-topics

Anatomy

1.1.9 Outline the features of a synovial joint.

Topic 1Anatomy

• Articular Capsule Synovial membrane

• Synovial fluid Bursae

• Articular Cartilage Meniscus

• Ligaments




IB


Sub-topics

1.1.9 Outline the features of the synovial joint

Topic 1

Anatomy




IB


Sub-topics

Topic 1

Anatomy



1.1.9 Outline the features of the synovial joint


Freely movable (synovial) joints

The joint capsule is an outer sleeve that protects and holds the knee together.

The synovial membrane lines the capsule and secretes synovial fluid – a liquid which lubricates the joint, allowing it to move freely.

Femur

Tibia

Joint capsule

Synovial membrane

Synovial fluid

Ligaments hold the bones together and keep them in place.

Cartilage

Smooth coverings of cartilage at the ends of the bones stops them rubbing together and provide some shock absorption.



IB

Sub-topics

Anatomy

Features of a Synovial Joint

•The ARTICULAR CAPSULE surrounds the bones at a joint; it protects and holds the knee together.

•The SYNOVIAL MEMBRANE lines this capsule and secretes SYNOVIAL FLUID – a liquid which lubricates the joint, allowing it to move freely.

•BURSAE are small ‘purse’ like sacs filled with SYNOVIAL FLUID that provide a cushion between bones and tendons and/or muscles around a joint. This helps to reduce friction between the bones and allows free movement.

Topic 1Anatomy





IB

Sub-topics

Anatomy

Features of a Synovial Joint

•Smooth coverings of ARTICULAR CARTILAGE at the ends of the bones stops them rubbing together and provide some shock absorption.

•The MENISCUS are pads of cartilaginous tissue which act as shock absorbers between the joints.

•LIGAMENTS hold the bones together and keep them in place.

Topic 1Anatomy





IB

Sub-topics

Anatomy

1.1.9 Outline the features of a synovial joint.

Topic 1Anatomy





IB

Sub-topics

Anatomy

• MeniscusTopic 1Anatomy





IB

Sub-topics

Anatomy

Types of Joints

Ball and socket

Hinge

Pivot

Gliding

Condyloid

Saddle

Topic 1Anatomy




Types of synovial joints

In ball and socket joints, the rounded end of one bone fits inside a cup-shaped ending on another bone.

Ball and socket joints allow movement in all directions and also rotation. The most mobile joints in the body are ball and socket joints.

Examples: Shoulders and hips.

Hip



Pivot joints have a ring of bone that fits over a bone protrusion, around which it can rotate.

These joints only allow rotation.

Examples: The joint between the atlas and axis in the neck which allows you to shake your head.

Axis

Atlas



In saddle joints, the ends of the two bones fit together in a special way, allowing movement forwards and backwards and left to right, but not rotation.

Examples: The thumb is the only one.

Hinge joints – as their name suggests – only allow forwards and backwards movement.

Examples: The knee and elbow. Elbow



Condyloid joints have an oval-shaped bone end which fits into a correspondingly shaped bone end.

They allow forwards, backwards, left and right movement, but not rotation.

Examples: between the metacarpals and phalanges in the hand.

Gliding joints have two flat faces of bone that slide over one another.

They allow a tiny bit of movement in all directions.

Examples: between the tarsals in the ankle.


Synovial joints – sporting examples

During the butterfly stroke, the ball and socket joint of the shoulder allows the swimmer’s arm to rotate.

You might head a football using the pivot joint in your neck, which allows your head to rotate.

What type of joint allows a handball player’s fingers to spread apart so that they can control the ball with one hand?


Synovial joints – sporting examples

The saddle joint allows the thumb to curl around a canoe paddle to give a firm grip.

Can you think of a sporting movement that involves the gliding joints between the tarsals?

The hinge joint at the knee allows the leg to flex and extend, for example when a hurdler extends their trail leg at take-off and then flexes it as they clear the hurdle.


Can you remember all these keywords?

Joint – a place where two or more bones meet.Ligaments – strong, elastic fibres that join bones together.Tendons – non-elastic fibres that attach muscles to bones.Cartilage – connective tissue found at the ends of bones to

protect them and enable smooth movement.

© Boardworks Ltd 20061 of 37 IB Sports, exercise and health science Sub-topics Anatomy The...

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