T Nation

What came first? The Nerve or the Hormone?

I was talking to a friend who asked me this question, and I think you guys can help out. In terms of I guess stimulation, what effects what first? Is it the nerve that stimulates the hormone production? or does the hormonal release trigger nerves? I’m thinking of this in application to lifting weights- getting psyched up for a lift, or even any other application. Thanks

The nervous system works much faster than the endocrine system. It’s kind of like comparing a telegraph to the pony express. The nervous system is hard wired and signals are transmitted from the brain to their destination directly and rapidly, if not instaneously.

The endocrine system on the other hand relies on the less precise and much slower circulatory system to send the message where it is going. It is even less sophisticated than say the pony express, because the message meanders wherever the circulation goes and may even get delivered to everyone in the neighborhood before it gets to the right address.

Think of it this way, when you think about extending your knee, it happens immediately (nervous system). If you got psyched up to do knee extensions, a neural signal has to go to your adrenal glands and elicit epinephrine release, epinephrine has to get into the circulation and may need to circulate for many seconds until the concentration level is high enough to affect anything.

So maybe a more apt comparison would be the telegraph vs. a slow boat to China.

That being said, the nervous transmitter associated with high stress (norepinephrine) can act as a hormone and spill over affecting surrounding tissues. There is a lot of interplay and similarities (epinephrine vs. norepinephrine) between the nervous system and the endocrine systems.

Good point, thanks for the info.