The most important thing about what are hormones, involves communication and signaling. Our bodies use them as vital information. They affect things like our distribution of fat, our appetite, fertility, the 3F’s (fighting, fleeing and mating), immunity, emotions and motivation.
In humans, communicating from one part of our bodies to another is incredibly complex. If we were simple organisms we could send a message directly like with a telephone wire system.
Imagine you have to take a message from one side of town to another and put it inside. How would you know when you reached your destination? It would have the right address and your key would fit the lock. Hormones work like this. They can only get into cells where their key fits.
How hormones work
Hormones find their target cells by receptors on that cell. If the key fits the lock, the door opens. A hormone not intended for a particular cell won’t be able to get in or deliver its message. Hormones affect the target cells with matching receptors (they actually change the cells behavior).
They have no affect on cells without the receptors. Sometimes the target cells are in a single place, other times they are scattered throughout the body. We produce more than 2000 hormones, so maybe you can appreciate how amazing this communication system is.
Hormones are incredibly powerful; a tiny amount can have a large impact on our bodies functioning. Because of this, our bodies regulate them carefully, mostly using negative feedback to achieve balance. Meaning when a gland senses there is too much of the hormone it stops producing it or sends a message to another gland to inhibit the hormone. It’s like standing on one leg, when your body senses itself tipping to one side, it tips to the other.
When hormones get out of balance they can seriously affect our health. For instance, when cells become insensitive to insulin, the pancreas keeps pumping out insulin even though there is plenty circulating in the blood stream. Eventually the pancreas becomes exhausted and can’t keep up with the demand. Blood sugar can be at toxic levels, but the body can’t deal with it.