Muscles shrinking when not used is the body being economic.
Muscles are made up of cells, and cells are living things. Living things need energy - food, one way or another, only to remain alive.
So even if you aren't using them at the moment, it's costing the body an effort only to keep them around.
And the body is economic. It doesn't like to spend effort on something that isn't being used.
If you're not using a muscle(much), the body will eventually stop maintaining those muscle cells it doesn't need. And the muscle as a whole will begin to shrink. It'll shrink to the point where what remains is what it needs to be able to do what you normally ask it to do.
Atrophy.
atrophy
Humans may get weak in a lack of gravity situation, due to the lack of use of certain muscles.
they are called caultonary muscles. YOU want to use them
Absolutely Your body uses sleep as a rebuilding time for muscles. Your muscles use energy most efficiently. If they never have time to recover then they cannot work properly. Therefore your energy can be depleted. However, lack of energy can be a sign of more serious issues such as anemia or thyroid problems. If this is an on going problem you should definitely consult your physician.
when the muscles expand or stretch. please don't use wikianswers to do your homework or a test that's called cheating... use ur notes!
Endurance
you use your leg muscles alot and your arm muscles. you use your leg muscles alot and your arm muscles.
Disuse of a muscle causes atrophy, which is a shrinking of muscle fibers leading to weakness. With use, the atrophy can be reversed.
You use the muscles in your body.
Because if you don't use it, then you lose it.
Your body uses sleep as a rebuilding time for muscles. Your muscles use energy most efficiently. If they never have time to recover then they cannot work properly. Therefore your energy can be depleted. However, lack of energy can be a sign of more serious issues such as anemia or thyroid problems. If this is an on going problem you should definitely consult your physician.
You use it to get into the "ship in a bottle" in Captain Crawfish's dream.
Anorexia essentially starves the msucles. Those who suffer with anorexia often exercsie a lot, and so strain and pressure it put on the muscles. This makes them more prone to injury and fatigue, even more so due to a lack of proper nutrients. Without enough fat stores in the body and with a lack of porper calorie intake daily, the body will eventually also begin to digest and use up muscles for energy. It will weaken your muscles and you will become very thin and skinny and unhealthy!