Transcript muscular system

Begin
The Muscular System
Yeah…just like that!
#1 Review
Function = job
Structure = a part/object
Homeostasis = keeping balance in the body. Equilibrium inside.
Stimulus : Response = how the body responds to changing
conditions
#2 Muscular System Overview
What makes up the most weight in your body? Bones? Fat? Skin?
Fingernails? Something else?
Of course, it’s muscle!
The same goes for
a cow. All those cuts
of beef that we like
are just the cow’s
muscles surrounded
by fat. Yep!
Your muscles do more
than just move you
around, though. Let’s
see.
#3 Muscular Sys. Overview
You have over 600 muscles responsible for moving body parts,
but many more muscles work internally to keep you going.
The muscular system consists of all the muscles in your internal
organs, as well as those attached to bones.
#4 FUNCTIONS of the
Muscular System
How do muscles cause movement? Well, muscles are masters of
pulling on bones. They can’t push at all—they’re not built that way.
But they can pull, pull, pull.
1. moves body parts by contracting (getting shorter)
2. controls life functions (breathing, heartbeat, digestion,
etc.)
#5 Muscle Control
Can you rub your tummy while you pat your head? Try it.
Whether or not you succeeded, you at least were able to move around
and give it a shot because you wanted to.
Now, stop your heart from beating. If you can’t, make your stomach
quit squishing up your most recent meal.
Some muscles are controllable by your thinking, other’s aren’t!
A voluntary muscle can be controlled by thinking. For example,
the biceps of your upper arm.
Involuntary muscles automatically contract on their own, such as
your stomach.
#6 STRUCTURES—Types of
Muscle
Muscles aren’t all built the same way, because they have different
jobs to perform. The STRONGEST muscles you have are the ones
that you’d use to shove a refrigerator around or swing a golf club
hard with. They’re strong, but tire pretty quickly.  These are called:
1. skeletal muscles
Two things about skeletal muscles:
a.) they’re all voluntary
and
b). they are attached to bones & structures
needing movement
#7 Structures/Types of
Muscle, contd.
Skeletal muscles that move your body around come in two varieties:
flexors and extensors. Flexors and extensors usually work in pairs,
as seen here:
i. flexor – bends a joint (biceps)
ii. extensor – straightens a joint (triceps)
biceps bends triceps
straightens it
the arm
#8 Structures/Types of
Muscle, contd.
Another type of muscle, called smooth muscle, is found lining the
internal organs. Acting like rings of rubber bands, they are good at
changing the shape and thickness of organs like your intestines, your
bladder, and your blood vessels.
2. smooth muscles
a. they’re involuntary, working
automatically
b. found in internal organs
(intestines, blood vessels)
Layers of smooth muscle make
the stomach able to grind food
#9 Structures/Types of
Muscle, contd.
Not EVERY one of your internal organs uses smooth muscle to run,
though. We’ve already talked about your heart and its never-resting
job. The heart is made of cardiac muscle, which never has to rest to
keep going for as long as you live.
3. cardiac muscle
a. involuntary, thankfully
b. found only in the heart
so, those are the three types
of muscle, what they do, and
where they’re found!
#10 DISORDERS of the
Muscular System
Let’s not play around. Come here, Joe.
Please, please,
please no
osteoporosis!
No worries, Joe.
Osteoporosis was a
skeletal system
disorder. You’re
safe.
#11 Disorders, contd.
There are many reasons why someone would be confined to a
wheelchair. Brain or nerve damage (paralysis) could be one, but
another genetic birth defect that affects thousands around the country
is muscular dystrophy.
Muscular dystrophy is a disease where a person’s muscles weaken
after birth and the sick have little control over them. Over time,
people with M.D. will often end up in wheelchairs as their muscles
fail them. Their minds are completely healthy, though. No cure
currently exists for this disease. The MDA (Jerry’s
Kids) is the most prominent charity searching for a
cure.
#12 Disorders, contd.
The drive to be bigger, “better” looking, or an improved athlete has
caused people to pursue any means possible to achieve these goals.
*sigh* Looks like Joe’s got quite a goal set for himself.
#13 Disorders, contd.
Joe gets to work…
…and finds that instantaneous
results aren’t exactly happening.
Like so many people, Joe gets
frustrated, wants the easy way
to success, and looks for a short
cut.
#14 Disorders, contd.
Joe meets up with a shady character known to provide illegal drugs
at the local gym. Which drug is Joe after?
Dang, Joe, what
Anabolic steroids.
are you doing?
You’re breaking
the law, spending
a lot of money,
and you’re about
to wreck your body
when some hard
work & persistence
would’ve gotten you
where you wanted.
#15 Disorders, contd.
The steroids work. That’s why so many people risk so much—jailtime,
humiliation, losing friends, families, careers, and even permanent
health problems and DEATH. Joe is so single-minded, though, that
those risks don’t matter to him. He’s just glad they work.
We’ve got to keep this powerpoint rated PG, so
we’re going to have to skip the health problems
that are about to affect Joe. Sorry.
However, please realize that abusing anabolic
steroids doesn’t just cause embarrassing side
effects.
Joe is now at risk for several LIFETHREATENING conditions that could easily
KILL him. You’ll read more about another day.
#16 Disorders, contd.
Joe made a bad, horrible choice. If he was doing the steroids to
make him better at sports, he’d be nothing but a cheater. In this
case, all he cheated was his health, which is never, ever worth it.
Steroid abuse can lead to dozens of side effects
due to way too many hormones. The effects can
be embarrassing to deadly. Here are just a few:
Men: shrunken genitals, stunted growth, cancer
Women: shrunken breasts, body hair, cancer
This should be an easy decision for everyone.
Anything illegal that has to be injected to work
is illegal for a reason. Stay off the roids.
#17 Review
Why is the muscular system important? What if Joe’s disappeared?
Function 1: allows for movement
Joe would collapse to the ground and never be able to eat, drink, or
fight off any attacker. He’d die of thirst, starvation, or being eaten by
fire ants.
Function 2: used in internal organs for life functions
Joe would instantly empty his bladder, he’d, uh, poop his pants, he’d
stop digesting his food, he’d stop Help!?!
moving air in & out of his body,
and his blood would come
to a standstill. Give him
about 5 minutes, max.
#18 Review, contd.
Homeostasis?
The muscles in your body keep your bloodflow and breathing going at
whatever rate your body needs at the moment. Also, they allow you to
digest food, eliminate certain wastes, and can even warm your body up.
Stimulus : Response
How about…
You are feeling really cold : your body shivers, trying to warm you up
#19 And That’s…