Slides in this set
The Skeletal System
The internal skeleton of vertebrates are needed for:
Support and movement
Store mineral e.g. calcium and phosphorus
Make red blood cells, platelets and some white
blood cells in the bone marrow
Protecting internal organs e.g. cranium (skull)
protects the brain…read more
The skeleton is made from tissues e.g. bones and
cartilage. This means they are living cells.
Bones are often broken down and rebuilt again.
This adaptability allows:
1. A child's bones to grow in size
2. An adults bone growth to increase in density due
to weight-bearing exercise such as jogging. Being
inactive makes the bones less dense and weaker.
IMPORTANT: You must understand that the internal skeleton of
vertebrates is needed for support and movement.…read more
Joints and movement
Holding bones together
There are 2 joints which you must know and they
1. Ball and socket joint: Most versatile. Can move in
any direction. E.g. hip or shoulders.
2. Hinge Joint: Can only move backwards and
forwards. E.g. knee and elbow.…read more
Ligaments are tough elastic bands which hold the
bones together and limit the amount of movement a
bone can make.
Smooth cartilage between two bones prevents the
bones from grinding against each other.
In case this cartilage wear away due to friction, the
joint is lubricated with synovial fluid which is oily.
There is a
image in your
text book on
IMPORTANT: You must know the structure and function of the components of a joint, to
include: a) smooth layer of cartilage and synovial fluid to reduce friction between bones. B) elastic
ligaments to stabilize joints while allowing movement. C) tendons to transmit the forces between
muscle and bones.…read more
How muscles move bones
Tendons are used to transmit the forces from
muscle to bone. The way movement works is
through antagonistic pairs.
1. One muscle contracts to bend the joint
2. The other muscle contracts to straighten joint
can be found Antagonistic Pairs: Two
muscles that work to
in text book
move the same bone in
on page 21 opposite directions e.g.
the bicep and triceps
IMPORTANT: You must understand that muscles can only move bones
at a joint by contraction, and thus operate in antagonistic pairs.…read more