Download Lesson 21 – Skeletal System

The Skeletal System
The skeletal system is made up of all the bones of the body. The skeletal system
has five functions during physical activity that you need to know.
1) Movement: along with muscles, they help us move our body.
2) Shape: the general nature of our bones gives us our shape – Mr Yates has
some very long bones making him tall. Dilawar has some very small bones,
making him a midget.
3) Support: they provide a frame for our muscles to attach to.
4) Protection: bones help to protect the vital organs from damage.
5) Production of Blood Cells: bones are where the body produces red and
white blood cells.
(GCSE PE: Unit 1.2.2)
The Skeletal System
In order to understand these functions you need to know the different bone types and
know some specific bones.
There are four different types of bones in the human body:
1) Long bones – these are lengthy bones mostly found in our limbs (arms and
legs). They help provide movement.
2) Short bones – these are small bones that produce little movement and
main function is to provide support (examples include the wrist and foot
bones)
3) Irregular bones – these are weirdly shaped bones that do not fit into any
other category.
4) Flat (plate) bones – these are strong, flat plates of bone which often
provide a protective layer for vital organs or are where muscles attach.
(GCSE PE: Unit 1.2.2)
Head bones
1. CRANIUM
TYPE: Flat
•The cranium is more
commonly known as the
skull.
•Its main function is to
protect the brain from
any damage.
(GCSE PE: Unit 1.2.2)
Upper Body
bones
1. RIBS
TYPE: Long
•The ribs form a cage and
protect a number of body
organs including the
lungs.
2. STERNUM
TYPE: Flat
•The sternum is flat bone that sits on the front of the ribs in the middle of your
chest.
•It adds extra protection for your heart muscle.
(GCSE PE: Unit 1.2.2)
Arm bones
1. HUMERUS
TYPE: Long
•The humerus is the only bone in the upper
arm.
•Its main function is to help with movement of
the entire arm limb but it also provides support
for the biceps and triceps muscles.
2. ULNA & RADIUS
TYPE: Long
•The ulna and radius attach to the wrist and
elbow, forming our lower arm.
•Their main function is to help with movement
of the lower arm.
(GCSE PE: Unit 1.2.2)
Hip bones
1. PELVIS
TYPE: Flat
•The pelvis is also known
as the hip bone.
•It provides protection for
reproductive organs but
also provide support for
muscles such as the gluteus
maximus.
(GCSE PE: Unit 1.2.2)
Leg bones
1. FEMUR
TYPE: Long
•The femur is the large bone in the upper leg.
•Its main function is to help with movement of the legs but it
also provides support for muscles such as the quadriceps and
hamstrings.
2. TIBIA & FIBULA
TYPE: Long
•The tibia (slightly bigger) and fibula make up the lower leg.
•Their main function is to help with movement of the lower leg
and feet but they also provides support for the gastrocnemius
muscle.
3. PATELLA
TYPE: Irregular
•The patella is also known as the knee cap.
•It provides protection for the knee joint from injury.
(GCSE PE: Unit 1.2.2)
Back bones
1. VERTEBRAE
TYPE: Irregular
•The vertebrae are small,
irregular bones that make
up the spinal column.
•They help provide
movement in the back,
whilst also shaping the
body.
(GCSE PE: Unit 1.2.2)
The Skeletal System - Joints
Where two bones meet in the body a
joint is formed. Joints where movements
(such as flexion, extension and
adduction) occur are known as synovial
joints.
There are three types of synovial joint
that you need to know about and each
allows different movements.
1) Ball & Socket joint: examples
include the shoulder and the hip.
2) Pivot: example is the neck joint.
3) Hinge: examples include the knee
and elbow.
(GCSE PE: Unit 1.2.2)
Different Types of Joint
The three different joints have different
characteristics:
1) Ball & Socket joint:
-
Its movement is like a PS4 controller joystick
It allows movement in a number of directions
(including rotation, adduction and abduction in
the shoulder and flexion/extension in the hip).
2) Pivot:
-
Its movement is similar to a washing machine
drum.
Allows a medium amount of movement (including
rotation in the neck).
3) Hinge:
-
Movement is like a door opening an closing.
Only allows movement in one direction
(flexion/extension in elbow/knee)
(GCSE PE: Unit 1.2.2)
Parts of a Joint
1) Tendons:
Strong, non-elastic tissue that
attaches muscles to bone.
2) Ligaments:
Tough, elastic fibre that attach
bone to bone at a joint.
3) Hyaline Cartilage:
Tissue found at the end of bones
that stops bones banging
together – Mr Yates has
damaged this in his femur which
is why he walks with so much
$WAG (*limps).
4) Synovial Fluid:
Found inside the joint, it works
like oil and keeps the joint
working smoothly.
5) Synovial Membrane:
This is the lining inside a joint
and is the place where synovial
fluid is produced.
The Effects of Exercise & Diet on the Skeleton
Exercise and diet can both have an effect on our skeletal system.
DIET. Eating foods high in calcium (milk, cheese) leads to more calcium
being stored in the bones. This makes the bone stronger, helping it to
support muscles and protect vital organs.
DIET. Eating foods high in vitamin D can help the body absorb more calcium.
EXERCISE: Weight-bearing exercise (walking, running, weight-lifting) where
there is some impact on the bones can help increase bone density. A higher
bone density reduces the chance of injury, improves posture and reduces
the chance of osteoporosis (where bones become weak and fragile).
EXERCISE: Exercising for a long period of time also helps strengthen the
tendons and ligaments. These means joints have more support and become
more stable. It also increases the production of synovial fluid, making the
joint more flexible.
(GCSE PE: Unit 1.2.2)
Injuries & the Skeletal System
We have looked at muscle injuries but sport can also lead to bone/joint injuries:
BONE INJURIES:
Injury
Description
Fracture
Happens when a force on the bone is stronger than the
bone itself. There are FOUR types (commonly known
as breaks)
1. Compound
(open) Fracture
The bone breaks completely and the broken end
comes through the skin.
2. Simple
The bone breaks completely but it all happens under
(closed) Fracture the skin.
3. Greenstick
Fracture
Pressure or impact buckles or bends a bone, cracking
it slightly but not causing a total break.
4. Stress
Fracture
Caused by overuse. Starts off as a small crack but gets
worse as you continue to use it.
(GCSE PE: Unit 1.2.2)
Injuries & the Skeletal System
We have looked at muscle injuries but sport can also lead to bone/joint injuries:
JOINT INJURIES:
Injury
Description
Overuse Injury
(Soft Tissue)
Using a joint repeatedly can cause tendons to become
inflamed (tennis elbow)
Dislocation
One of the bones at a joint comes out of place during a fall
or a blow to the area.
Sprains
(Soft Tissue)
Ligament fibres get torn when a joint is overstretched or
twisted.
Torn Cartilage
(Soft Tissue)
Small tears appear in the cartilage at the end of a bone.
(GCSE PE: Unit 1.2.2)
Treating Injuries
In order to treat soft tissue joint injuries you should use the RICE
procedure:
Rest: Firstly you should rest the inured part, preventing further damage.
Ice: Applying ice to the injury helps prevent swelling and pain.
Compression: Putting a bandage or strapping around the injured area
helps with support and should reduce internal bleeding/swelling.
Elevate: It is important to lift the injured part to reduce swelling and
painful throbbing (resting it on a box/bench/chair etc). Ideally the injured
part should be raised above the level of the heart as this will stop
internal bleeding.
(GCSE PE: Unit 1.2.2)