Transcript The Skeletal and Muscular Systems

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http://highered.mheducation.com/sites/dl/free/0078617022/161752/00053415.h
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Because of the way we
usually see bones, it’s easy
to think of them as dry and
lifeless.
The fact is they are neither
dry nor lifeless
Bones are living organs
made of several different
tissues.
They are moist, supplied
both blood and lymph
vessels, as well as nerves,
bones are as much organs
as are the heart and brain.
The average human
adult has 206 bones.
 Bones support and
protect parts of the body.
 They work with your
muscles so you can
move.
 They help you maintain
homeostasis by storing
minerals and making
blood cells
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Bones are made of
connective tissue and
minerals.
There are two different kinds
of bone tissue:
Compact bone: dense and
rigid, does not have open
spaces.
Spongy bone: many open
spaces, provides most of the
strength.
Bones also contain a tissue
called marrow, which
produces blood cells and
stores fat
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When you were born, you
didn’t have much true
bone.
What you had was
cartilage, which is soft and
rubbery.
As you grew, most of the
cartilage was replaced by
bone.
Most bones still have
cartilage at the ends.
This cartilage cushions the
areas where bones meet
(joints)
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A place where two bones meet is
called a joint.
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Your joints allow you to move
when your muscles contract.
Some joints, like those in your
skull allow for little or no
movement.
Other joints, like those in your
shoulder allow for many
movements
Joints are held together by
ligaments, which are strong
bands of connective tissue
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EQ: How do organ systems work together to enable an organism to maintain
homeostasis?
 Your
skeletal system
does not work alone!
 Muscles connect to
your skeleton and they
contract and move the
skeleton along (you
use over 200 muscles
each time you take a
step!)
Muscle is an organ that
contracts and expands,
creating movement.
 In your body there are
more than 600 muscles.
 Muscles not only help
you move, they also give
your body shape and
produce heat in your
body.
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Most of the meat on our
bones is muscle.
 There is so much of it, it
makes up about 40% of
our total body weight.
 Available in all shapes
and sizes, muscles
shorten on command,
stretch when necessary,
and then bounce back to
their normal resting
strength.
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There are two main groups
of muscle, voluntary and
involuntary.
https://www.youtube.com/
watch?v=w6k5tzFbfa4
Voluntary muscles are
muscles your control
consciously (you have to
think about how and when
to move them)
Involuntary muscles are
those that work
automatically (you don’t
have to think about them)
You
have three types of muscle
tissue in your body:
Skeletal
Smooth
Cardiac
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These muscles move
bones.
They are attached to bones
by tendons (thick bands of
tissue)
They are voluntary
muscles.
They are the most common
type of muscle in your
body.
They are striated (striped).
They contract and expand
quickly.
Involuntary (work
automatically)
 Found in the walls of
many of your organs,
such as your intestines,
blood vessels and skin.
 They move the organs as
needed.
 They contract and relax
slowly.
 They are not striated
 They are thin muscles
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 Only
found in the
heart.
 It is involuntary
 It is striated.
 It contracts nonstop all
day and night for your
entire lifetime!
 Your
muscular system
is very closely
connected to the
nervous system.
 This makes sense
because you usually do
not have to think to
keep your heart
beating, your internal
organs working or even
before you move.
What
are the organs and
functions of the skeletal and
muscular systems?
How do the skeletal and
muscular systems interact?