GCSE Physical
Education
The Skeletal System
The skeleton
 How
many bones are there in the
human body?
206
There are
206 bones
in the
human body
- the larger
bones are:
Skull
Scapula
(hidden)
Clavicle
Sternum
Vertebrae
Humerus Radius
Metacarpals
Phalanges
Ribs
Ulna
Carpals
Pelvis
Femur
Patella
Tibia
Fibula
Phalanges
Tarsals
Metatarsals
The Skeleton

Facts & Information
There are 206 bones in the body
 28 bones in the cranium
 12 pairs of ribs (bottom 2 pairs are floating)

Bones stop growing in length after about 16-18 years
but continue to increase in density.
 After about 35 years bones begin to deteriorate.

What are the main functions
of the skeleton?
Aids Movement
Protects vital
organs
Supports Muscles
FUNCTIONS OF THE
SKELETON
Red blood cell
production
in bone marrow
Gives body shape
Epiphsysis
The end of a long bone
Diaphysis
The shaft of a long bone
Cartilage
A dense, elastic connective tissue which
cushions and connects many bones in the
skeleton
Periosteum
A tough membrane which surrounds the bone
Compact
bone
A substance beneath the periosteum, forming
the shaft of a long bone
Cancellous
bone
A spongy substance found inside the compact
bone.
Calcium
Mineral that is vital for healthy bones
Types of Bones
There are 3 main types of bones in the human body.
Each type has a different size and shape because they
have different jobs to do:
Long Bones – For blood production, support
and movement. These are long and affect our
overall height, e.g. the legs & arms (femur &
humerus).
Flat Bones – These are flat and are often
found forming a protective surface, e.g. the
skull (cranium) and pelvis.
Irregular Bones – These are irregular in shape
and have a specific function, e.g. the bones of
the spine (vertebral column).
The Skeleton

Axial Skeleton

Consists of:





Skull
Vertebral column
Ribs
Sternum
Appendicular skeleton

Consists of:




Arms
Legs
Shoulder girdle
Hip girdle
The Vertebral Column
Movement:
The joints in the spine allow bending and
twisting.
Support:
The spine is long and strong to support other
body parts, e.g. the head.
Protection:
The spine is hard and protects the nerves
running through the middle, i.e. the spinal cord.
It is made up of 34 vertebrae, which are divided
into 5 regions, each having its own function.
The Vertebral Column

Supports body parts, lets you bend
and twist, and protects the spinal
cord

It is made up of 34 vertebrae:
 Cervical vertebrae (7)
 Support the neck and the head
 Thoracic vertebrae (12)
 Connected to the ribs
 Don’t move much – protect the heart
and the lungs
 Lumbar vertebrae (5)
 Allow twisting and turning
 Sacrum (5 fused)
 Fused to the pelvic girdle
 Solid base for the trunk & legs
 Coccyx (5 fused)
 Remains of the tail
Joints
http://www.youtube.com/watch?v=BXoMa2bVC18&feature=related
Joints
 Name
as many different joints as you
can.
 Can
you identify the bones articulating at
each joint?
Types of joints
There are 3 main types of joint found in the body.
1. Fixed or Immoveable Joints
The bones at an immoveable joint cannot move they overlap or interlock, and are held together
by a tough fibre, e.g. the skull.
2. Slightly Moveable Joints
The bones at a slightly moveable joint can only move
a little - they are held together by strong straps
called ligaments and are joined by protective pads
known as cartilage, e.g. the ribs.
3. Freely Moveable Joints
At a freely moveable joint the bones move freely.
They are also known as synovial joints, and
are the largest group of joints found in the body,
e.g. the hips, shoulders and knees.
Joints

The human skeleton is jointed to
allow movement.

Muscular contraction causes the
bones to move about the joints.

The bones act as levers with the
joints acting as pivots.
A joint is where two or more bones meet and
muscles act together to cause movement.
Freely Moveable Joints



Freely Moveable joints are also known as Synovial Joints.
They are freely moving and occur where 2 or more bones meet.
There are about 70 freely moveable joints in the human skeleton.
A typical synovial joint has the following characteristics:
1. Cartilage – A material which covers the end of each bone, and
which helps prevent friction between the joint.
2. Joint Capsule – The outer covering of the joint that holds
the bones together and protects the joint.
3. Synovial Membrane – The inner lining of the joint
capsule which also produces synovial fluid.
4. Synovial Fluid – The fluid which surrounds the joint and
acts like an ‘oil’, lubricating it to allow easy movement.
5. Ligaments – These are elastic straps which join bone to
bone, holding the joint together.
6. Tendons – These are non-elastic straps which join muscle to bone.
Examples of Synovial Joints
Hip Joint
This joint can be moved in the
following ways:





Bend
Straighten
Circle
Move away from the body
Move towards the body
Elbow Joint
This joint can be moved
in the following ways:


Bend
Straighten
Shoulder Joint
This joint can be moved in the
following ways:





Bend
Straighten
Circle
Move away from the body
Move towards the body
Knee Joint
This joint can be moved in
the following ways:


Bend
Straighten
Wrist Joint
This joint can be moved in the following ways:





Bend – but not as much as the knee & elbow.
Straighten - but not as much as the knee & elbow.
Circle – but not as much as the shoulder & hip.
Move away from the body – but not as much as the shoulder & hip.
Move towards the body – but not as much as the shoulder & hip.
Types of Synovial Joints
Freely moveable (synovial) joints can be
divided into six groups depending upon
how they move.
KEY
Ball & Socket Joint
Hinge Joint
Pivot Joint
Gliding Joint
Saddle Joint
Condyloid Joint
1. Ball and Socket Joints
Ball and Socket joints are the most moveable joints in the body.
They can move in all directions, e.g. the hip and shoulder joints.
2. Hinge Joints
Hinge joints work like a hinge on a door.
They can only move in two directions, e.g. the knee and elbow joints.
3. Pivot Joints
This joint only allows rotation,
e.g. the vertebrae of the neck.
4. Gliding Joints
There is a little movement in all
directions, e.g. the hand between
the carpals.
5. Saddle Joints
In these joints there is movement
forwards, backwards and to the
right and left, but no rotation,
e.g. the thumb.
6. Condyloid Joints
Here there is a little movement in
all directions, but there is no
rotation, e.g. the wrist.
The Synovial Joint of the Knee
The knee is a hinge joint.
Cartilage
Synovial Membrane
Patella
Tendons
Femur
Ligaments
Synovial Fluid
Tibia/Fibula
The Synovial Joint of the Hip
The Hip is a ball and socket joint.
Cartilage
Pelvis
Synovial
Membrane
Synovial Fluid
Ligaments
Tendons
Femur