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Healthy Bones - Contenido educativo

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Subido el 28 de mayo de 2007 por EducaMadrid

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NASA Connect Segment explaining the importance of good nutrition and specifically nutrients such as calcium. The video explores bones and effects on astronaut's bones.

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Thanks, Jennifer. Hi, my name is Scott Smith. I'm the lead for NASA's Nutritional Biochemistry Laboratory. 00:00:00
Jennifer provided you some great background information on the importance of good nutrition. 00:00:06
Based on the information she provided, can you come up with a definition for nutrition? 00:00:10
What is your daily nutritional need for calcium? How are you meeting that need? 00:00:14
In your groups, take a few minutes to answer the questions. 00:00:18
Your teacher can now pause the tape so you can collaborate with your peers. 00:00:21
Nutrition is the study of how the body uses nutrients, like calories, vitamins, and minerals, 00:00:24
and how much of each of those nutrients the body needs. 00:00:29
While good nutrition is important for everybody, 00:00:31
NASA scientists at the Nutritional Biochemistry Laboratory look at how astronauts' nutrient needs are affected by spaceflight. 00:00:33
One area that is very important is the role of nutrition in keeping bones healthy. 00:00:39
Not eating foods that include nutrients such as calcium and vitamin D can result in weak bones. 00:00:42
You can find good sources of calcium and vitamin D in dairy products such as milk and cheeses, broccoli, and spinach. 00:00:48
Calcium is probably the most important nutrient that comes to building strong bones. 00:00:54
More than 99% of the calcium in your body is stored in bones, 00:00:58
and when you don't get enough calcium in your diet, it comes out of bones to help the other tissues. 00:01:01
If you do that long enough, what happens is the bones become weak and brittle, and can lead to diseases such as osteoporosis. 00:01:06
Osteoporosis is a disease where the bones become fragile and break. 00:01:12
The best way to counteract or prevent getting osteoporosis is to eat well and exercise when you are young. 00:01:15
So why are we concerned about bone loss during spaceflight? 00:01:21
Astronauts actually lose bone mass during spaceflight. 00:01:24
This is especially significant for long missions such as the astronauts that serve on the International Space Station, 00:01:27
or on future missions to other planets. 00:01:32
When astronauts return from long missions, 00:01:34
they have an increased risk of fractures and other health problems because they lose bone mass and calcium. 00:01:36
Do you have any idea why this occurs? 00:01:41
Does that mean they get osteoporosis while they're in space? 00:01:43
The human body gets used to operating in Earth's gravity field. 00:01:46
When humans are removed from this environment, as when they travel in space, many complex changes take place. 00:01:49
While living and working in a microgravity environment, 00:01:54
your body senses that it doesn't need as much bone mass to support the body, so bone mass decreases. 00:01:56
When you return to Earth's gravity environment, 00:02:01
your body senses it needs more bone mass to support the body, so bone mass will begin to increase. 00:02:03
Because it takes a long time to regain the lost bone, 00:02:08
this is the period when you have a higher risk of bone fractures 00:02:11
because your body's skeleton has a tougher time supporting your body against Earth's gravity. 00:02:14
Here at NASA, we conduct research to understand how much calcium is being deposited into bones 00:02:19
and how much calcium is being taken out of bones. 00:02:23
This research involves mathematics, especially measurement and estimation skills. 00:02:25
For example, let's take a look at the following system diagram. 00:02:29
Suppose Norbert was to consume 1,000 milligrams of calcium, 00:02:32
which is the daily recommended allowance, in the form of a large glass of milk. 00:02:35
This diagram shows the path that calcium and other nutrients follow as they enter Norbert's body from the mouth. 00:02:39
The milk enters the stomach and is broken down in the stomach and small intestine by chemical processes. 00:02:45
Approximately 80% of the calcium, or 800 milligrams, leaves the body as solid waste. 00:02:50
The remaining 20%, or 200 milligrams of calcium, enters your bloodstream. 00:02:55
The calcium will help many of your body functions 00:02:59
and, importantly, will prevent calcium from being taken out of bones. 00:03:02
This is what happens when you don't eat enough calcium. 00:03:05
About 5%, or 50 milligrams of the remaining calcium, 00:03:08
enters your kidneys and is released as liquid waste. 00:03:11
Some of the calcium will be taken up into bone, 00:03:14
and some will also be released by bone back into the bloodstream. 00:03:16
Finally, a small percentage of calcium flows from the bloodstream into the large intestine and out as solid waste. 00:03:19
To estimate how much calcium bones are absorbing and how much calcium is being taken out of bones, 00:03:25
we can give Norbert a tiny amount of a special form of calcium. 00:03:29
For this case, let's call it blue calcium. 00:03:32
Over time, usually 10 to 14 days, 00:03:35
we collect biological samples of solid waste, liquid waste, and blood. 00:03:38
We can determine how much calcium, regular or blue, is in each sample. 00:03:42
By mathematically analyzing the data, we can actually estimate 00:03:46
the amount of calcium absorbed by the intestines, 00:03:49
how much calcium is filtered by the kidneys, 00:03:51
how much calcium is being deposited into bone, 00:03:53
and how much calcium is being taken out of bone. 00:03:56
By studying the flow of calcium before, during, and after spaceflight, 00:03:58
we can tell how the body is changing during flight and what is happening to the calcium. 00:04:01
From our estimates, we can conclude that the amount of calcium that is deposited into bone 00:04:06
and the amount of calcium released by the bone back into the blood is about the same. 00:04:10
This changes when astronauts are in space. 00:04:14
The amount of calcium absorbed by the bone is less than the amount of calcium released by the bone. 00:04:16
Finally, when astronauts return to Earth and recover over time, 00:04:20
the amount of calcium deposited into bone and the amount of calcium released by bone stabilizes 00:04:24
and returns to pre-flight levels. 00:04:28
Understanding the specific means of how bone and calcium use change during flight 00:04:30
can help us figure out how to counteract it and also help prevent bone disorders on Earth, 00:04:34
such as osteoporosis. 00:04:37
Are you beginning to understand the importance of nutrition 00:04:39
and how nutrition can be important for your health? 00:04:41
Have you changed any of the answers to the questions I asked earlier? 00:04:43
Now would be a great time to stop the tape and review your answers. 00:04:46
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Idioma/s:
en
Materias:
Matemáticas
Niveles educativos:
▼ Mostrar / ocultar niveles
      • Nivel Intermedio
Autor/es:
NASA LaRC Office of Education
Subido por:
EducaMadrid
Licencia:
Reconocimiento - No comercial - Sin obra derivada
Visualizaciones:
329
Fecha:
28 de mayo de 2007 - 16:51
Visibilidad:
Público
Enlace Relacionado:
NASAs center for distance learning
Duración:
04′ 51″
Relación de aspecto:
4:3 Hasta 2009 fue el estándar utilizado en la televisión PAL; muchas pantallas de ordenador y televisores usan este estándar, erróneamente llamado cuadrado, cuando en la realidad es rectangular o wide.
Resolución:
480x360 píxeles
Tamaño:
29.30 MBytes

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