Transcript Unit 1: The Body in Action

Unit 1:
Types of Joints
Learning Objectives
• All students will be able to describe what joints are
• All students will be able to classify joints into one of three categories
• All students will be able to identify the six different types of synovial
joints
• Some students will be able to explain why different classifications of
joints allow different ranges of movement
Joint movement – what are joints?
• A joint is a place where two or more
bones meet.
• 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. Immovable (or fixed) joints
2. Slightly movable joints
3. Movable (or synovial) 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.
•Where can these be found in the body?
• 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.
bone
cartilage
bone
ligaments
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.
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
Synovial
membrane
Different types of joint
Freely movable (synovial) joints
The joint capsule is an outer sleeve
that protects and
holds the knee together.
Synovial
fluid
The synovial membrane
lines the capsule and secretes
synovial fluid – a liquid
which lubricates the joint, allowing it
Cartilage
to move freely.
Femur
Tibia
Smooth coverings of cartilage at the ends
of the bones stops them rubbing together
and provide some shock absorption.
Ligaments hold the bones together and keep them in place.
Synovial
membrane
Joint capsule
Synovial Joints
There are six different types of synovial joints:
Please use this website very informative
http://oldlearnzone.loucoll.ac.uk/NLN/Science/Biology/Life%20Sciences/workshop3_RH4_Joint%20structure%20and%20functio
n/69EC3221-AE3F-41A9-AED0-4092E5834A91/485_sco.html
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Hinge Joint
Ball and socket joint
Ellipsoid (condyloid joint)
Gliding Joint
Pivot Joint
Saddle joint
Activity 1
Working in pairs.
Provide a description of the six different joint of
the skeleton, providing examples.
Ball and Socket Joints
In ball and socket joints, the
rounded end of one bone fits
inside a cup-shaped ending
on another bone.
Hip
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.
Pivot Joints
Pivot joints have a ring of bone that fits
over a bone protrusion, around which it
can rotate.
These joints only allow rotation.
Atlas
Examples: The joint between the
atlas and axis in the neck which
allows you to shake your head.
Axis
Saddle Joints
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.
Ellipsoid (Condyloid) Joints
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
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.
Hinge Joints
Hinge joints – as their name
suggests – only allow forwards
and backwards movement.
Examples: The knee and elbow.
Elbow
Types of synovial joints
Activity 2
In the same pairs you were in earlier: You need to provide a sporting
example for the use of each joint.
For example: During the butterfly stroke, the ball and socket joint of the
shoulder allows the swimmer’s arm to rotate.
What would happen to the performance if there was another type of
synovial joint present?
(You might have to present back to the rest of the class)
Class Discussion
Why do some joints allow for different
ranges of movement?
Joint movement – how do we move?
Movements
What other movements are we missing?
Working with a partner:
Take it in turns to demonstrate a simple sporting
movement, for example performing a biceps curl or
taking a step forward.
Together, analyze the movement and decide what
types of movement are occurring at each joint.
Now take it in turns to name a joint. Ask your
partner to demonstrate and name all of the
movements possible at that joint.
For example, the hinge joint at the elbow shows
flexion, extension and slight rotation.