5.4 different kinds of joints
TRANSCRIPT
Content Purpose• Students will be able to:• understand what is a joint;• name the 3 types of joints;• name the 2 main causes of joint
injuries.
Language Purpose• Fixed / Immoveable joints
• Slightly moveable joints• Freely moveable joints• Ligaments• Joint cavity• Synovial membrane
Social Purpose• One conversation• No sleeping• Putting of palm on whiteboard• Class too noisy and need to
quieten down
Between connecting bones…The bones connected together by
ligaments (strong fibres)The area where two or more
bones meet is called a joint
Ligament
Joint
Types of JointsThere are 3 types of joints
◦Fixed / Immoveable joints◦Slightly moveable joints◦Freely moveable joints
Fixed or Immoveable JointsAlso known as fibrous jointsJoints with very tough fibre to prevent
movement between the connecting bones
Can you think of any immoveable joints?
Fixed joints
Fixed or Immoveable JointsWhy would we want immoveable
joints?◦Eg. Skull (cranium)◦Babies are borned with the plates in
the cranium not joined together◦Facilitates birth / delivery◦The plates are joined after birth to
provide protection for the brain
Slightly Moveable JointsAlso known as cartilaginous jointsAllow very small amount of
movementJoints are connected by cartilageCan you name some slightly
moveable joints?
Slightly Moveable JointsThe connecting cartilage acts as
a cushioning layer (shock absorber) between the bones
The bones serves largely as protective layer for important parts of the body
But allows slight movement to facilitate day-to-day actions◦Eg. Bending of back, breathing
Freely Moveable JointsMore commonly known as
synovial jointsAllow a large degree of
movementExist 4 different types which
allow different kind of movement◦Ball and socket◦Hinge◦Pivot◦Gliding
Covering in next lesson
Trivia…
◦ Bones pulled further apart◦ Expansion of the synovial
membrane◦ Results in temporary
expansion of synovial cavity
◦ Increase volume = decrease pressure
◦ Cavitation (formation of air bubbles)
◦ When pressure over-reduced, the bubbles burst, thus the “CRACK” sound
◦ Not medically proven to be harmful till date
What happens when you crack your knuckles (joints at the finger)?
Joint InjuriesJoint injuries come in few forms:
◦Bone injuries Wear and tear Impact
◦Ligament injuriesMost common joint injuries
happened on◦Knee◦Ankle Why?
Our KneeOther components of knee joint
◦ Articular cartilage – Protects end part of femur and tibia.
◦ Meniscus – Additional cartilage material between femur and tibia for shock absorption
◦ Ligaments – Strong fibres holding femur and tibia together
Knee InjuriesMeniscus tear – Happens when
there’s sudden movement of twisting, pivoting, or being tackled
Other Joint InjuriesMore joint and bone related
injuries will be covered in the later part of the term