The Skeletal System
BONES
Functions:
• 1. Mechanical
• Support – bones are
the framework for the
attachment of muscles
and other tissues
• Movement – bones
enable the body
movements by acting
as levers and points of
attachment for
muscles so they pull on
the bone when the
muscle contracts
Function:
• 2. Protection
• The skull and ribcage
protect vital organs
from injury
• Bones protect
marrow (the inside of
the bone) which
creates new blood
cells
Function:
• 3. Metabolic (Production)
• Mineral storage – bones store
essential minerals, like
calcium, which are released
throughout the body when
needed
• Blood cell production – Blood
cell formation occurs in the
red marrow found within the
cavities of certain bones
• Red bone marrow produces red
blood cells and white blood
cells
• Energy storage – fats stored in
the yellow marrow serve as
energy storage
• Found in long bones (arm and leg
bones)
What are bones?
• Bones are made up
of living cells and
store minerals.
• If bones break, they
can heal
Bones have jobs?
• The skull
• This is an important
bone because it
protects your brain,
which is very soft. It
also gives your face
its’ shape.
The side
view of the
skull
Jobs
• The Spinal Column
• also known as the
backbone
• It is attached to your
skull and made up of
small bones stacked
on top of each other.
It supports your head
and body and has
muscles and nerves
that run along it.
Jobs:
• The Ribs
• There are 12 pairs of
flat bones to form a
cage. It protects your
heart and lungs, and
involved with
breathing (like we
just learned!)
Jobs:
• Arm and Legs
• Each arm has one
bone that runs from
your shoulder to your
elbow (the
humorous), and two
bones from your
elbow to your wrist
(radius and ulna).
Jobs:
• Your leg bones begin
at your hip, and run
down to your knee
(the femur) and then
there are two bones
that make up your
lower leg (the tibia
and fibula)
How do bones move?
• Your bones would not be able to move without
joints. A joint is formed where two bones meet.
• Some joints allow a lot of movement, like your
knee joint, and others only allow a little or no
movement, like your skull.
• Ligaments are strong, elastic fibers that stretch
and tighten like rubber bands. The hold the
bones of the joints together.
• Cartilage is a layer of gel material that reduces
friction between your bones at the joints. It acts
like a cushion for your joints when you jump.
Example of a joint: Knee
Critical Challenge Time!