Not one specific person discovered medicine
The 650 skeletal muscles in the human body contract when they receive signals from motor neurons, which are triggered from a part of the cell called the sarcoplasmic reticulum. Motor neurons tell your muscles to contract and the better you become at having those signals tell your muscles to contract, the stronger you can get.
That is TRUE because when you get older your bones and muscles start to decrease so being physically active will make your bones and muscles stronger as they decrease.
Answer:
Explanation:
Because most people do not look inwardly at what they do, think or feel. It is a very difficult task to look at yourself with stark naked honesty. For example, what do you think when you break up with someone? Do you automatically think it is the other person's fault, or do you look to your own part of what has happened? Most people don't ever think o f their own part; they're two busy nursing the pain.
Answer:
the stairs you can stretch ur back in many ways
