4
votes
1answer
71 views

What causes humans to be sleepy?

Is there a hormone or group of hormones that regulates when we feel sleepy late at night, or in the morning? Or is sleepiness caused by some other non-hormonal mechanism? (e.g. pure psychological, ...
4
votes
3answers
161 views

Biological Pathway of Lipid Hypothesis

I've read a lot on both sides of the debate of low carb vs low fat diets trying to make some sense of what is being proposed. The lipid hypothesis runs roughly along the lines that we have lots of ...
7
votes
1answer
351 views

Single hormone opposite effects

Often, a smooth response to a hormone means that some processes must be sped up and others must be slowed down. How can a single hormone have opposite effects like this?
8
votes
3answers
195 views

Can elements of one's environment act directly as hormones?

Can pollution and things in an organism's environment serve as hormones?