Download The Skeletal System

The Human Body Lesson
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The skeleton is a living
thing.
There are 206 bones in
your body. (unless you
had an accident with
some power tools.)
Babies have about 350
bones when they are
born. They are made of
cartilage and haven’t
grown together yet.
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There are 4 types of
bones; long, short, flat,
irregular.
Long- femur,
humerus,radius, ulna.
Short-carpals, tarsals
Flat-cranium, ribs,
sternum
Irregular- vertebrae,
sacrum, coccyx.
These are the
catacombs of
Paris where
millions of
people’s
remains can
be found lining
the walls.
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There are actually two
skeletons inside of you.
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The Axial Skeleton is the
skeleton you must have
to live.
Your chest and cranium.
The Appendicular
Skeleton is made of
bones and limbs you can
live without.
Your arms, legs, hands,
feet.
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After 911, more
than 1300 soldiers
have lost limbs
during combat.
New advances in
prosthetics are
always needed.
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Tendons are strong,
cords that connect the
muscle to bone.
Ligaments are tough,
rubberband-like tissue
that connect bones to
other bones.
Marrow is the soft tissue
inside of bones that
make blood cells.
It produces about 5
billion red blood cells a
day!
Ligaments
connect bones
to other bones.
I’m sorry to say that
there is no such thing as
“double-jointed.” I
know, let me guess, you
know someone who can
bend their arm or finger,
or elbow really weird.
Sorry, they still aren’t
double jointed. These
people only have longer
tendons and ligaments
either naturally or from
stretching them over
time.
The outer walls of
bones are made of a
dense tissue called
compact bone.
 The inside of bones is
made of a softer tissue
called spongy bone.
 Spongy bone’s more
scientific name is
“Cancellous Bone”
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A joint is a place where
two bones meet.
 There are five movable
joints and one nonmoving joint.
 Your skull has a special
joint called a fixed
joint. The bones are
locked in place and do
not move.
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Ball and Socket These allow
circular movement. Found in
your shoulders and hips.
Hinge joints allow movement
in one direction. Found in
your elbows and knees.
Pivot This joint is found only
in your neck. Allows you to
look up, down, side to side.
Gliding(Sliding) Bones slide
on a disc of cartilage. Found
in your backbone.
Saddle Allows movement in
two directions. Found in your
thumb.
She can do this
because of the
gliding joints in
her back.
The longest bone is
your femur.
 The smallest is the
stirrup found in your
ear.
 Dislocated Bones are
bones that have been
knocked out of place.
Owie!
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Fractures are breaks in
bones.
 Simple Fractures are
cracked bones.
 Compound Fractures
are when the bone
breaks but then pushes
through the skin.
DOUBLE OWIE!
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