SKELETONS AND
JOINTS
FUNCTIONS
• SHAPE AND SUPPORT – provides a frame
• MOVEMENT – occurs where bones meet
• PROTECTION – surrounds vital organs
• BLOOD PRODUCTION – made in bone
marrow
FUNCTION - SHAPE AND
SUPPORT
• Provides a framework to support all
organs, muscles and other components
of the body
• Determines shape and size of the body
e.g. taller people have longer bones
FUNCTION - MOVEMENT
• Where 2 bones meet is called a JOINT.
• Movement occurs at the joint when muscles
on either bone that meets at the joint
contracts.
• This is called ARTICULATION
• The joints with the greatest range of
movement are the shoulder, elbow and wrist,
and the hip, knee and ankle.
FUNCTION - PROTECTION
• The skeleton provides a protective
‘cage’ around vital organs of the body.
• The ribs protect the heart and lungs.
• The skull protects the brain.
• The pelvis protects the abdomen.
• The vertebral column protects the
spinal chord.
FUNCTION - BLOOD
PRODUCTION
• Blood contains both red and white blood
cells.
• Red cells carry oxygen to the muscles.
• White cells fight infection in the body.
• Blood cells are produced in the BONE
MARROW inside the long bones of the
body.
TYPES OF BONE
• There are 3 main types of bone.
• LONG –
found in the arms and legs. They are the
‘levers’ of the body where a lot of movement happens
e.g. humerus, radius, ulna etc.
• FLAT – plate-like bones that have a large surface
area for protective purposes e.g. cranium, scapula,
pelvis etc.
• IRREGULAR –
serves a protective function e.g.
the vertebrae protect the spinal chord.
BONES AND MOVEMENT
• OVERHEAD CLEAR IN BADMINTON –
– Long bones (humerus, radius, ulna,
phalanges and metacarpals).
– Flat bones (scapula, clavicle).
– Irregular bones (carpals).
What bones are involved in a golf swing,
throwing a javelin, and kicking a ball?
SYNOVIAL JOINTS
• Synovial joints are enclosed within a
synovial capsule.
• Synovial fluid lubricates the joint for
smooth movement.
• Cartilage covers the end of the bones in
the joint and acts as a shock absorber.
• Ligaments attach bone to bone and
provide stability at the joint.
• Tendons attach muscle to bone.
SYNOVIAL JOINTS
PROPERTIES OF CARTILAGE,
LIGAMENTS AND TENDONS
CARTILAGE LIGAMENTS TENDONS
•Smooth and tough
•Tough and flexible
•Tough
•Slightly flexible (for
impact)
•Connects 2 bones
together
•Prevents easy
dislocation (stabilises
the joint)
•Restricts excessive
movement
•Non-elastic
•No blood vessels
•Shock absorber
between bones
•Prevents bones from
wearing away by rubbing
against each other
•Many fibres
•Attaches muscle to
bone
•Transfers force from
muscle to bone, creating
movement
TYPES OF MOVEMENT
• FLEXION - reducing the angle
between 2 bones at a joint
e.g. bending at the elbow in a bicep
curl
TYPES OF MOVEMENT
• EXTENSION – increasing the angle
(straightening) between 2 bones at a
joint
e.g. straightening the knee to kick a
ball
TYPES OF MOVEMENT
• ROTATION – movement around an
axis point (swivelling)
e.g. turning your head to the side to
breath when swimming
TYPES OF MOVEMENT
• ABDUCTION – taking a limb away
from the central body line
e.g. an outwards kick in karate
TYPES OF MOVEMENT
• ADDUCTION – taking a limb towards
the central body line (across the body)
e.g. a left hook in boxing
TYPES OF SYNOVIAL JOINT
• BALL AND SOCKET – one end of a
bone is rounded (like a ball) and fits into a hollow
socket at the end of the other bone.
• Where? –
shoulder (clavicle and humerus) and hip
(pelvis and femur).
• Movement –
rotation, flexion and extension,
adduction and abduction (greatest range of
movement).
e.g. bowling in cricket,
overhead clear in
badminton.
TYPES OF SYNOVIAL JOINT
• HINGE – 2 bones meet at either end and are
connected by ligaments to stop dislocation.
• Where? –
knee (femur and tibia/fibula) and elbow
(humerus and radius/ulna).
• Movement –
flexion and extension only.
e.g. kicking a ball
bicep curl
press-ups.
TYPES OF SYNOVIAL JOINT
• GLIDING – small bones move over one
another to allow flexibility.
• Where?
–
hands (carpals/metacarpals) and
feet (tarsals/metatarsals).
• Movement
–
flexion and extension through
hands and feet
e.g. pointing toes in gymnastics.
TYPES OF SYNOVIAL JOINT
• PIVOT – the end of 1 bone has a ‘peg’
that fits into a ‘ring’ formed by the other
bone.
• Where? – cranium and spinal column (neck).
• Movement – rotation.
e.g. turning head to the
side to breath in
swimming.