Transcript for NASA Connect - Good Stress

[00:00:24.008]
Hi, I'm Lisa Leslie, pro basketball
player for the Los Angeles Sparks.

[00:00:28.498]
Though I'm very talented
athletically,

[00:00:30.458]
I'm even more talented
academically.

[00:00:32.378]
I'm here because, like you, I
believe in the value of education,

[00:00:38.448]
its capabilities to
enlighten and enrich, and,

[00:00:41.898]
if we believe strong enough,
to transform our lives.

[00:00:46.588]
While playing pro basketball,
I earned my graduate degree

[00:00:49.468]
in business administration.

[00:00:51.328]
Please don't sell yourself short
by not performing well in school.

[00:00:55.138]
The key to life is
getting a good education,

[00:00:57.048]
and it starts when you're young.

[00:00:59.428]
On this episode of NASA
Connect, you'll learn all

[00:01:02.058]
about building better
muscles and bones.

[00:01:04.578]
And just like education, the
key to building better muscles

[00:01:07.708]
and bones also starts
when you are young.

[00:01:10.928]
So stay tuned as host
Jennifer Pulley takes you

[00:01:13.198]
on another exciting episode
of NASA Connect: "Good Stress:

[00:01:17.578]
Building Better Muscles and Bones."

[00:01:21.088]
[Music]

[00:01:30.088]
[00:01:50.468]
Hi, I'm Jennifer Pulley,
and welcome to NASA Connect,

[00:01:54.888]
the show that connects you to math,

[00:01:56.978]
science, technology, and NASA.

[00:02:02.918]
I don't know how you deal with
stress after a long day at school,

[00:02:05.488]
but for me, after
work, I hit the gym.

[00:02:07.878]
You know, stress can be
caused by many things

[00:02:10.888]
such as being overworked,
mentally tired,

[00:02:14.308]
or just overwhelmed
by our daily lives.

[00:02:17.578]
In fact, how many
of you get stressed

[00:02:20.158]
out over an important test?

[00:02:22.818]
I get stressed when I don't
have enough time in the day

[00:02:25.508]
to complete all my work.

[00:02:27.228]
Does that mean that
stress is a bad thing?

[00:02:30.118]
While too much stress can
be damaging to the body,

[00:02:33.198]
too little of some kinds of
stress can also be harmful.

[00:02:36.808]
Let's look at three
types of stress.

[00:02:39.338]
The first is called
physical stress.

[00:02:42.318]
Activities like walking

[00:02:43.948]
and carrying textbooks
are physical stresses.

[00:02:47.128]
The second stress,
called mental stress,

[00:02:50.568]
involves activities like doing
math problems or taking quizzes.

[00:02:55.278]
The third type of stress
is called emotional stress.

[00:02:58.478]
It can be either good or bad,
like winning "Science Student

[00:03:02.318]
of the Year," or receiving
a bad grade on a test.

[00:03:06.348]
Our bodies, including muscles
and bones, require some physical

[00:03:10.598]
and mental stress, or good
stress, to be healthy and grow.

[00:03:15.168]
In today's program, we will
focus on good stress and how

[00:03:18.928]
to build better muscles and bones.

[00:03:21.318]
We will also learn how
NASA researchers collect

[00:03:24.578]
and analyze data to better
understand how our muscles

[00:03:28.088]
and bones are constantly changing,

[00:03:30.098]
especially in a microgravity
environment.

[00:03:33.908]
That's RJ.

[00:03:34.968]
He's a friend of mine who's an
up-and-coming cross-country star.

[00:03:38.118]
He had an injury a few months
ago, but I think his injury

[00:03:41.248]
and today's program
have a lot in common.

[00:03:43.868]
RJ, what's up?

[00:03:45.338]
Hey, Jen. I tore a
muscle in my leg,

[00:03:47.198]
and I've been immobilized
for a few months.

[00:03:49.128]
I'm trying to get
my leg strength back

[00:03:50.518]
to where it was before the injury.

[00:03:52.458]
Well, you know, it looks like you
were doing some rehabilitation.

[00:03:54.548]
How's that going?

[00:03:55.338]
I'm really struggling.

[00:03:56.598]
In fact, I've been struggling
for the past two weeks.

[00:03:59.088]
I'm a keeping a log of my
workouts, but I can't figure

[00:04:01.338]
out if my rehab's on target.

[00:04:02.988]
You mean you're having
trouble analyzing your data.

[00:04:05.018]
I think so.

[00:04:07.038]
Well, I think I can help
you and your leg out.

[00:04:10.478]
You know, data analysis
is the math focus today.

[00:04:13.988]
So you mean my leg is going to
be the focus of this program?

[00:04:18.018]
I guess you could look
at it that way, RJ.

[00:04:19.668]
To better understand
your leg injury, yes,

[00:04:21.758]
you do need to understand
data analysis.

[00:04:24.888]
Now, before we help RJ
out, there are a few things

[00:04:27.098]
that you need to know.

[00:04:28.678]
During the course of this
program, you will be asked

[00:04:31.188]
to answer several
inquiry-based questions.

[00:04:34.088]
After the questions
appear on the screen,

[00:04:36.498]
your teacher will pause the
program to allow you time to answer

[00:04:40.308]
and discuss the questions.

[00:04:42.098]
This is your time to explore
and become critical thinkers.

[00:04:45.838]
Students, working in
groups, take a few minutes

[00:04:48.848]
to answer the following questions:
Number one, what is data?

[00:04:55.128]
List some examples of data.

[00:04:56.588]
Number two, where
do data come from?

[00:05:01.748]
Number three, why do data
need to be interpreted?

[00:05:06.568]
Compare your answers
to all three questions

[00:05:09.838]
with other groups in your class.

[00:05:11.738]
It is now time to
pause the program.

[00:05:14.078]
So did you come up
with some good answers?

[00:05:17.078]
Good job. Data are
the facts, figures,

[00:05:21.358]
and other evidence gathered
through observations.

[00:05:25.158]
You might collect data on
the number of boys and girls

[00:05:27.968]
in your math class, the types
of animals in a local zoo,

[00:05:31.728]
or the average monthly
temperatures where you live.

[00:05:35.178]
Besides collecting your
own data, you might be able

[00:05:38.158]
to find data already collected
in journals, newspapers,

[00:05:42.558]
almanacs, or even the Internet.

[00:05:45.148]
Once you collect the data you
need, then you must interpret,

[00:05:49.018]
or analyze, that data.

[00:05:50.938]
At NASA, researchers are constantly
on the lookout for patterns

[00:05:55.238]
that can help them
understand how things work.

[00:05:58.048]
By analyzing data, they can
describe relationships between

[00:06:02.138]
and among numbers and the
scientific principles they

[00:06:05.398]
are investigating.

[00:06:07.018]
Before you analyze the data, it's
very helpful to arrange the results

[00:06:11.298]
in an organized way
such as a chart.

[00:06:14.588]
Graphing your results will help
you visualize your findings.

[00:06:18.728]
By organizing and
visualizing the data,

[00:06:21.808]
you can look for patterns
and trends.

[00:06:24.568]
For example, let's take
a look at RJ's data.

[00:06:26.378]
RJ, what do you have for us?

[00:06:28.368]
Well, the display shows the amount
of weight my right leg can lift

[00:06:31.528]
when doing a set of ten repetitions

[00:06:33.038]
on a leg-extension machine.

[00:06:34.878]
The data was taken over
a four-month period.

[00:06:38.048]
So it looks like your data are
organized by time and weight.

[00:06:42.008]
You know, a scatter plot would
be an awesome graph to use

[00:06:45.658]
to help you analyze this data.

[00:06:46.878]
A scatter plot?

[00:06:48.698]
Yeah, a scatter plot is a graph
that shows the relationship

[00:06:51.928]
between two variables,
like time and weight.

[00:06:54.758]
Scatter plots let you visually
determine whether the trend

[00:06:58.588]
in your data is positive,
negative, or none at all.

[00:07:04.888]
In your case, the two
variables are time and weight.

[00:07:09.798]
To make a scatter plot, we
plot these two variables

[00:07:13.118]
as ordered pairs.

[00:07:15.438]
Here's what the scatter
plot looks like.

[00:07:17.938]
The x-axis is the time, and the
y-axis is the amount of weight.

[00:07:24.168]
And don't forget, you always
need a title for your plot.

[00:07:29.348]
Can you determine a trend or
relationship in the scatter plot?

[00:07:34.038]
In other words, does the
data show a positive trend,

[00:07:38.448]
negative trend, or no trend at all?

[00:07:41.998]
This would be a great
time to pause the program

[00:07:44.888]
and discuss the relationship with
your fellow students and teachers.

[00:07:48.738]
It's now time to pause the program.

[00:07:50.978]
Well, RJ, what can you
determine from the plot?

[00:07:53.588]
I notice that my leg strength
increased between March and May.

[00:07:57.188]
But over the last month, my leg
strength has remained constant.

[00:08:00.318]
You know, RJ, you're right.

[00:08:01.958]
You did have a positive
trend for a couple of months.

[00:08:04.888]
But I wonder why you leveled off.

[00:08:07.188]
You know, I know someone at NASA
who is the lead astronaut strength,

[00:08:10.938]
conditioning, and
rehabilitation specialist.

[00:08:13.168]
Her name is Beth Shepherd,
and I bet she could help you

[00:08:15.398]
out with your rehab program.

[00:08:16.828]
Here's her contact information.

[00:08:18.788]
Give her a buzz.

[00:08:20.028]
Thanks, Jennifer,
for all your help,

[00:08:21.458]
especially learning
how to analyze data.

[00:08:23.218]
I'll talk to you later?

[00:08:24.078]
Okay. Let's see what he can learn
from Beth Shepherd about muscles,

[00:08:28.038]
bones, and rehabilitation.

[00:08:29.738]
Hi, RJ. Welcome to NASA
Johnson Space Center.

[00:08:35.388]
Thanks, Ms. Shepherd.

[00:08:36.438]
Please, call me Beth.

[00:08:37.568]
Okay, Beth.

[00:08:39.448]
Jennifer called to tell me
you're having some problems

[00:08:41.368]
with your rehab.

[00:08:41.828]
I sure am.

[00:08:43.528]
She thought maybe you could help.

[00:08:45.188]
Jennifer told me that you're
the lead astronaut strength,

[00:08:47.448]
conditioning, rehabilitation
specialist.

[00:08:49.658]
That's right.

[00:08:50.718]
My job is to physically
prepare astronauts

[00:08:52.658]
for long-duration space missions
through cardiovascular exercise,

[00:08:56.028]
muscle strength and
endurance weight training,

[00:08:58.088]
as well as balance,
coordination, and agility drills.

[00:09:01.148]
It looks like I've come
to the right place.

[00:09:03.478]
Did you bring your data?

[00:09:04.248]
It's all right here in my Palm.

[00:09:07.508]
What does this graph represent?

[00:09:09.958]
The scatter plot represents
the amount

[00:09:11.548]
of weight my right leg can lift
when doing a set of ten repetitions

[00:09:15.028]
on a leg extension machine.

[00:09:16.768]
The data was taken over
a four-month period.

[00:09:19.248]
I need some help figuring out why I
leveled off during the past month.

[00:09:22.578]
What kind of muscle
tear did you have?

[00:09:24.738]
I remember my doctor telling me it
was some kind of skeletal muscle.

[00:09:28.668]
I'd never heard the term
"skeletal muscle" before.

[00:09:31.338]
Let me give you a crash course
on the basics of muscles.

[00:09:33.638]
Okay. This would be a great time
to pause the program to answer

[00:09:38.038]
and discuss the following
questions: What are some types

[00:09:41.018]
of muscles in your body?

[00:09:43.668]
Why do astronauts' muscles
weaken while working in space?

[00:09:48.018]
What are some ways to
take care of your muscles?

[00:09:50.398]
It is now time to
pause the program.

[00:09:53.638]
Your body has three different types
of muscle tissue: skeletal muscle,

[00:09:57.048]
smooth muscle, and cardiac muscle.

[00:09:59.418]
Skeletal muscles are attached
to the bones of your skeleton.

[00:10:02.628]
These muscles provide the
force that moves your bones.

[00:10:05.788]
They are also classified
as voluntary muscles,

[00:10:08.248]
meaning you have control over them.

[00:10:10.448]
Smooth muscles can be found
inside of many internal organs

[00:10:13.118]
of the body, such as the walls
of the stomach and blood vessels.

[00:10:16.818]
They are classified as involuntary
muscles, meaning they are not

[00:10:20.098]
under your conscious control.

[00:10:21.898]
The last type of muscle, cardiac
muscle, is found only in the heart.

[00:10:25.638]
It has characteristics of both
skeletal and smooth muscles.

[00:10:29.128]
I didn't realize there
are different types

[00:10:30.338]
of muscles in my body.

[00:10:31.848]
Well, I definitely know now

[00:10:33.098]
that I tore a skeletal
muscle in my right leg.

[00:10:35.478]
I have control over it.

[00:10:37.368]
Okay, let's get back
to your problem.

[00:10:39.698]
Now, you've been doing the same leg
extension exercise throughout the

[00:10:42.288]
entire rehab, right?

[00:10:43.968]
Yes, I have.

[00:10:44.998]
It's my favorite leg exercise.

[00:10:47.338]
In order to stimulate
growth or recovery,

[00:10:49.268]
you need to change your
workout every four to six weeks.

[00:10:51.868]
If you do the same workout
program over a long period of time,

[00:10:54.588]
your body reaches a plateau.

[00:10:56.308]
And in your case, you reached
a plateau a few weeks ago.

[00:10:59.508]
Gee, I'd better change
my workout plan.

[00:11:02.168]
Practice for the cross-country
team starts in a few weeks,

[00:11:04.798]
and I want to make it
to the state finals.

[00:11:07.298]
What do you suggest?

[00:11:08.768]
Well, RJ, I would suggest
adding some variety

[00:11:10.688]
to your exercise program, such as
bicycling, swimming, rollerblading,

[00:11:14.868]
and resistive training
with your own body weight.

[00:11:17.088]
That sounds pretty cool.

[00:11:18.618]
So, Beth, what kind of rehab
program do astronauts go through?

[00:11:21.688]
That's a great question, RJ.

[00:11:22.748]
When astronauts return from
long-duration space flights,

[00:11:25.718]
their muscles and bones are weaker.

[00:11:27.048]
For example, astronauts in
space routinely use their arms

[00:11:30.468]
to move around, but they
don't use their leg muscles

[00:11:32.638]
to resist gravity.

[00:11:33.988]
The lack of muscle
force can cause muscles

[00:11:35.818]
to weaken or reduce in size.

[00:11:38.268]
The main focus of my job is to
prevent muscle and bone loss,

[00:11:40.858]
starting with pre-flight and
in-flight exercise programs.

[00:11:43.908]
But because we haven't figured out
how to completely prevent muscle

[00:11:46.878]
and bone loss, the focus

[00:11:48.358]
of the post-flight
rehabilitation program is

[00:11:50.338]
to return the astronaut's
muscle and bone back

[00:11:52.278]
to their pre-flight baseline.

[00:11:54.298]
My team develops exercise programs

[00:11:56.108]
that include cardiovascular
conditioning, muscle strength

[00:11:58.798]
and endurance, and
flexibility and agility drills.

[00:12:02.108]
Each astronaut has an
individualized program,

[00:12:04.678]
because the amount of muscle

[00:12:05.728]
and bone loss differs
for each astronaut.

[00:12:07.728]
That's really cool.

[00:12:08.938]
That sounds a lot like what
I'm going through right now.

[00:12:10.898]
It is very similar to your
rehabilitation program.

[00:12:13.838]
In fact, one of our
astronauts, Leland Melvin,

[00:12:16.218]
is doing a little rehab of his own.

[00:12:18.348]
Hi, Mr. Melvin.

[00:12:19.408]
Hey, RJ. How're you doing?

[00:12:20.878]
Are you rehabbing
your leg, as well?

[00:12:21.918]
I sure am; I re-aggravated my
hamstring muscle while playing

[00:12:25.398]
pro football.

[00:12:26.288]
Wow, a pro football player.

[00:12:28.788]
How did you go from
being a football player

[00:12:30.258]
to being an astronaut?

[00:12:31.768]
I injured my hamstring
muscle while in training camp

[00:12:33.908]
with the Detroit Lions, but
it never fully recovered.

[00:12:36.758]
In addition to working
hard at sports,

[00:12:38.968]
I did well academically in school.

[00:12:41.288]
Too many young athletes
today don't realize

[00:12:43.678]
that sports can only
take you so far in life.

[00:12:46.278]
My cross-country coach
emphasizes that all the time.

[00:12:48.748]
It's good grades in school that
will make me excel in life.

[00:12:51.938]
Sounds like you have a great coach.

[00:12:54.268]
So does your rehab program
require mainly stretching?

[00:12:57.238]
That's only one component.

[00:12:58.778]
Exercise, or good stress,

[00:13:00.338]
is important for maintaining
both muscular strength

[00:13:02.548]
and flexibility, and for recovery.

[00:13:05.038]
When you stretch and
warm up thoroughly,

[00:13:07.158]
your muscles become more flexible.

[00:13:09.268]
This helps prepare muscles
for the work involved

[00:13:11.508]
in exercising and playing sports.

[00:13:13.848]
Also, warming up the
muscles can prevent injuries.

[00:13:17.498]
Like with your hamstring?

[00:13:18.688]
Exactly, RJ.

[00:13:19.538]
If you overwork or overstress
your muscles, you can strain

[00:13:22.988]
or pull them, and that's
a form of bad stress.

[00:13:25.888]
Now, I pulled my hamstring
really bad,

[00:13:27.428]
and that was some serious pain.

[00:13:28.978]
Don't let it happen to you.

[00:13:30.378]
And if you pull a muscle,
you need to let it rest

[00:13:32.568]
until the muscle heals.

[00:13:34.148]
I sure did learn a lot
about muscles today.

[00:13:36.108]
Thank you so much for your help.

[00:13:37.228]
Oh, and by the way, you
mentioned that your job deals

[00:13:39.628]
with muscle loss and bone loss.

[00:13:40.928]
Do you know any good bone
specialists I can talk to?

[00:13:43.798]
That's right; you said you
were immobilized for some time.

[00:13:45.918]
Why don't you go and see
Dr. Sognier here at NASA?

[00:13:48.238]
And she can tell you
all about bones.

[00:13:50.408]
Thank you again, and
have a great day.

[00:13:52.458]
Mr. Melvin, you better take
care of that hamstring muscle.

[00:13:57.328]
Hey, thanks, RJ.

[00:13:59.548]
Take care.

[00:14:00.068]
Before RJ speaks with Dr.
Sognier, I think it's time for you

[00:14:04.218]
to strengthen your muscles and
increase your muscle stamina.

[00:14:08.108]
The students at Oxon Hill Middle
School will preview this program's

[00:14:11.898]
hands-on activity,
entitled "Good Stress."

[00:14:15.758]
Hi! NASA Connect asked us
to show you this program's

[00:14:18.328]
hands-on activity.

[00:14:19.808]
In this activity, you will be
exploring the effects of stress

[00:14:23.168]
on the muscles in your hands.

[00:14:25.978]
And you will gain experience
collecting, analyzing,

[00:14:29.508]
and visually representing data.

[00:14:32.538]
You can download a copy
of the educators' guide

[00:14:34.798]
from the NASA Connect website.

[00:14:37.338]
Before you begin the activity, it's
a good idea to review how to make

[00:14:41.858]
and interpret three types
of plots: scatter plots,

[00:14:46.768]
box-and-whisker plots,
and stem-and-leaf plots.

[00:14:52.018]
Do you remember what
a scatter plot is?

[00:14:54.578]
A scatter plot is a graph

[00:14:56.438]
that displays two
variables as ordered pairs.

[00:14:59.958]
You can use a scatter plot

[00:15:01.368]
to determine how one
variable relates to another.

[00:15:05.428]
A box-and-whisker plot is a graph

[00:15:07.978]
that summarizes a data
set along a number line.

[00:15:10.998]
There is a box in the middle
and whiskers at either side.

[00:15:16.248]
The least value of the data set
determines the left whisker.

[00:15:22.188]
The greatest value of the data
set determines the right whisker.

[00:15:26.868]
You form the box using quartiles.

[00:15:30.558]
Quartiles divide the data
into four equal parts.

[00:15:34.278]
Box-and-whisker plots are
useful with very large data sets

[00:15:38.368]
or for making comparisons
between data sets.

[00:15:41.498]
A stem-and-leaf plot is a graph
that uses the digits of each number

[00:15:46.918]
to show the shape of the data.

[00:15:49.198]
Each data value is broken into a
stem, digit or digits on the left,

[00:15:55.478]
and a leaf, digit or
digits on the right.

[00:15:59.778]
A key is needed to explain what
your stem and leaves represent.

[00:16:04.988]
A stem-and-leaf plot can quickly
show the distribution of a data set

[00:16:09.568]
and retains each data value.

[00:16:12.008]
Your teacher can show you example
problems using different plots.

[00:16:16.028]
Now, are you ready to put
your math skills to the test?

[00:16:19.018]
Good. Now back to the activity.

[00:16:21.628]
Working in groups of
two, predict the number

[00:16:24.258]
of times you will be able to click
a clothespin between your thumb

[00:16:28.638]
and index finger in
your non-dominant hand

[00:16:31.628]
for a one-minute period.

[00:16:33.988]
Record your prediction.

[00:16:35.168]
Hold the clothespin in
your non-dominant hand

[00:16:39.258]
between your thumb
and index finger.

[00:16:41.708]
While your partner is watching
the timer, count the number

[00:16:44.768]
of times you are able to click the
clothespin in a one-minute period.

[00:16:49.068]
Record the result.

[00:16:50.638]
Rest for one minute,
then predict again

[00:16:53.668]
and repeat clicking the
clothespin in a one-minute period.

[00:16:57.658]
You need to complete three trials.

[00:17:00.608]
Be sure to hold the clothespin the
same way during every time trial.

[00:17:05.448]
Now switch roles with
your partner, and have him

[00:17:08.448]
or her conduct the exact same
experiment and record the results.

[00:17:13.268]
Each group will need to repeat
the experiment every other day

[00:17:17.498]
for two weeks.

[00:17:19.278]
Record your predictions
and results.

[00:17:21.898]
This is the conditioning period.

[00:17:24.208]
The stress induced by the
clothespin on the muscles

[00:17:27.738]
of the hand will cause the muscles

[00:17:29.618]
to become stronger
and gain stamina.

[00:17:32.418]
Make sure you record all your
data in a clear and organized way.

[00:17:36.878]
This will help you to answer
all the discussion questions

[00:17:40.418]
and to produce visual
representations of the data.

[00:17:43.848]
And don't forget to check out the
web activity for this program.

[00:17:47.638]
It can be downloaded from
the NASA Connect website.

[00:17:54.958]
Great job, you guys.

[00:17:56.488]
Oh, talk about working
your muscles.

[00:18:00.108]
Well, now that you have a preview

[00:18:01.448]
of this program's
hands-on activity,

[00:18:03.328]
it's time to pause
the program to see

[00:18:05.298]
if you can increase your
muscle strength and stamina.

[00:18:08.538]
So how was the activity?

[00:18:12.858]
You'll probably be happy not

[00:18:14.048]
to see another clothespin
for a while, huh?

[00:18:16.428]
Hopefully, it reinforced
the math concepts

[00:18:18.538]
that you learned earlier
in today's program.

[00:18:20.588]
Now let's review.

[00:18:21.818]
First, we introduced to you
different kinds of stress

[00:18:25.358]
and how physical stress can
actually be good stress.

[00:18:28.648]
Next, you learned about the
math concept of data analysis

[00:18:33.598]
and how graphing is a
powerful way to visualize data.

[00:18:37.918]
Finally, Beth Shepherd and Leland
Melvin helped RJ and you learn

[00:18:42.758]
about taking care of your muscles.

[00:18:45.208]
Let's turn our attention to bones
now and see what we can learn

[00:18:48.848]
about our body's skeletal system.

[00:18:51.238]
Let's catch up with
RJ and Dr. Sognier.

[00:18:53.868]
[Knocking] Dr. Sognier?

[00:18:55.608]
Hi, RJ. Come on in.

[00:19:04.608]
[00:19:06.618]
Take a seat.

[00:19:07.388]
I understand you want to
learn more about bones,

[00:19:16.388]
[00:19:17.798]
their structure and function.

[00:19:19.328]
I sure do.

[00:19:20.428]
I want to be the best
cross-country runner in my state,

[00:19:23.468]
and knowing more about my body
might actually be an advantage.

[00:19:26.418]
And after meeting Leland Melvin, I
want to learn more about astronauts

[00:19:29.618]
and how their bones can be
affected by space flight.

[00:19:31.828]
Sure, I'd love to discuss your
body's skeletal system with you.

[00:19:36.298]
Students, working in
groups, take a few minutes

[00:19:39.768]
to answer the following questions:
What does a skeletal system do?

[00:19:45.008]
It may be helpful
to sketch a picture.

[00:19:48.828]
List some types of bones in your
body and explain their function.

[00:19:54.178]
[00:19:55.368]
What are some ways to
keep you bones healthy?

[00:19:58.648]
[00:19:59.708]
How are the skeletal and
muscular systems related?

[00:20:04.098]
[00:20:05.658]
It's now time to pause the program.

[00:20:08.948]
Without the skeletal system,
your body would collapse.

[00:20:13.548]
Your skeleton has many functions:
it provides shape and support;

[00:20:19.748]
protects your internal organs
like your brain, heart, and lungs;

[00:20:24.928]
enables you to move;
produces red blood cells;

[00:20:29.308]
and stores important minerals
until your body needs them.

[00:20:33.218]
You have about 206
bones in your body.

[00:20:36.928]
For example, your arm consists
of the humerus, radius, and ulna.

[00:20:44.558]
Your leg consists of the femur,
patella, tibia, and fibula.

[00:20:51.348]
All your bones are connected
to the vertebral column,

[00:20:54.268]
or backbone, in some way.

[00:20:56.798]
I mentioned earlier that the
skeletal system enables you

[00:21:00.238]
to move.

[00:21:02.038]
Most of the body's bones
are associated with muscles.

[00:21:06.368]
The muscles pull on the
bones to make the body move.

[00:21:10.188]
So the muscles and bones in
our bodies work as a system?

[00:21:13.398]
That's a great observation, RJ.

[00:21:15.228]
That's why we can't just learn
about muscles without understanding

[00:21:19.518]
about bones and vice versa.

[00:21:22.328]
Bones also store minerals such
as calcium and phosphorus.

[00:21:27.378]
These minerals make the
bones strong and hard.

[00:21:31.208]
They are packed tightly together.

[00:21:33.458]
In fact, bones are so strong
that they can absorb more force

[00:21:38.478]
without breaking than
concrete or granite rock,

[00:21:43.018]
and bones are much, much lighter.

[00:21:46.308]
Is there anything else in bones
besides calcium and phosphorus?

[00:21:49.838]
Yes, bones also contain
living cells and tissues

[00:21:54.138]
such as blood and nerves.

[00:21:56.448]
As you grow, new bone
tissue is produced.

[00:22:00.278]
Even after you are
grown, your bones continue

[00:22:03.318]
to form new bone tissue.

[00:22:05.498]
So what does the inside
of a bone look like?

[00:22:08.548]
Well, for example, let's look
at a femur, or thigh bone.

[00:22:15.348]
The femur, which is the longest
bone, connects the pelvic bones

[00:22:20.098]
to the lower leg bones.

[00:22:22.408]
Notice the thin, tough
membrane that covers all

[00:22:26.128]
of the bone except the ends.

[00:22:29.028]
Blood vessels and nerves enter

[00:22:31.498]
and leave the bone
through the membrane.

[00:22:34.748]
Beneath the membrane is
a layer of compact bone,

[00:22:38.688]
which is hard and dense.

[00:22:41.478]
Just inside the compact bone
is a layer of spongy bone.

[00:22:46.918]
Spongy bone is found
in the backbone

[00:22:49.918]
and at the ends of the bones.

[00:22:52.878]
Like a sponge, spongy bone has
many small spaces within it.

[00:22:58.668]
This structure makes spongy
bone lightweight but strong.

[00:23:03.378]
The spaces in bone contain a soft
connective tissue called marrow.

[00:23:09.398]
Because my leg was immobilized for
a period of time, does that mean

[00:23:12.848]
that the bones in my
leg were affected?

[00:23:14.718]
Sure, your bones were affected
-- not in terms of size,

[00:23:18.348]
but in terms of bone density.

[00:23:20.868]
So, RJ, do you have any idea
how to keep your bones healthy?

[00:23:25.048]
Well, I believe good nutrition
and exercise is the key

[00:23:27.858]
to strong and healthy bones.

[00:23:29.568]
Way to go, RJ!

[00:23:30.468]
You're pretty good.

[00:23:32.708]
I learned about good
nutrition and exercise

[00:23:34.488]
from the NASA Connect program,

[00:23:36.318]
"Better Health From
Space to Earth."

[00:23:38.358]
Go to the NASA Connect
website to learn more.

[00:23:41.538]
You know, RJ, a well-balanced
diet contains enough calcium

[00:23:45.228]
and phosphorus to keep your bones
strong while they're still growing.

[00:23:49.268]
Meats, whole grains, and leafy
green vegetables are all excellent

[00:23:54.268]
sources of both minerals.

[00:23:56.768]
Dairy products, including milk,
are excellent sources of calcium.

[00:24:02.018]
Exercise is also important to help
bones become stronger and denser.

[00:24:07.398]
But you don't have
a problem with that,

[00:24:09.338]
because you work out all the time.

[00:24:11.768]
I also learned that it's
important to develop good nutrition

[00:24:14.118]
and exercise habits
when you're young.

[00:24:15.988]
That's true.

[00:24:17.078]
It's very important, because your
body's bones are still growing.

[00:24:21.278]
Beth Shepherd told me earlier that
astronauts' bones become weaker

[00:24:24.608]
and smaller after they
return from space.

[00:24:27.108]
How much do they lose?

[00:24:29.228]
Well, it depends on
a number of factors,

[00:24:32.528]
such as space flight duration,
amount of exercise in space,

[00:24:38.288]
nutrition, and body chemistry.

[00:24:41.228]
Most of the bone loss occurs in
the lower portion of the body,

[00:24:45.038]
primarily from weight-bearing
bones.

[00:24:47.768]
One study we conducted on
astronauts on the ISS showed

[00:24:52.118]
that the mean, or average, bone
mineral loss in the hip portion

[00:24:56.648]
of the femur, or spongy
bone, ranged from 1

[00:25:01.028]
to 2.5 percent per month,
about 1.35 percent per month

[00:25:07.468]
in the pelvic region,
and 1 percent per month

[00:25:11.498]
in the lower back,
or lumbar region.

[00:25:13.778]
That's really interesting.

[00:25:16.358]
So what happens when
astronauts go to Mars and beyond?

[00:25:19.978]
If an astronaut loses about
1percent of their bone mineral

[00:25:23.028]
in the lower back per month,
then that means that he

[00:25:25.668]
or she will lose roughly
12 percent over a year.

[00:25:29.698]
Since the current missions
haven't lasted that long,

[00:25:32.758]
we don't actually know, but
it is likely, and, therefore,

[00:25:37.488]
we need to conduct more
research to know for certain.

[00:25:40.568]
You know, the more we can learn
about how our bodies function

[00:25:43.868]
in space, the closer we get
to developing countermeasures

[00:25:47.938]
that will significantly reduce
the effects of bone loss

[00:25:51.368]
and muscle loss while in space.

[00:25:54.268]
Space research is
important, because it helps us

[00:25:57.238]
to understand how our bodies
function here on Earth.

[00:26:00.118]
It is another tool to
help us combat diseases

[00:26:04.448]
such as the bone disease
osteoporosis.

[00:26:07.968]
Thanks, Dr. Sognier.

[00:26:08.808]
If you ever need assistance with
your research, just call me.

[00:26:12.358]
I'll do that, RJ.

[00:26:13.318]
And good luck with your training.

[00:26:16.698]
Okay, take it easy.

[00:26:18.828]
I think we'll be hearing more
from RJ in the years to come,

[00:26:24.808]
and hopefully we'll be
hearing more from you.

[00:26:27.498]
Don't forget to check out this
program's student challenge,

[00:26:30.328]
which can be found on
the NASA Connect website.

[00:26:33.378]
Well, guys, that wraps up
another episode of NASA Connect.

[00:26:36.068]
We'd like to thank everyone who
helped make this program possible.

[00:26:39.868]
Got a comment, question,
or suggestion?

[00:26:42.738]
Well, then, email them to
"connect at larc.nasa.gov."

[00:26:47.568]
So until next time,
stay connected to math,

[00:26:50.538]
science, technology, and NASA.

[00:26:52.838]
And remember the good
stress in life.

[00:26:55.518]
See you then.

[00:26:55.858]