Those of you who follow Holy Hormones Journal and Holy Hormones, Honey know our little world revolves around hormones. But are you aware of what hormones are and the role they play in your body?
The word “hormone” comes from the Greek word hormōn, meaning to ‘arouse’ or ‘excite’ or ‘to set in motion.’ Hormones keep your body functioning regularly by setting physiological processes into motion – from metabolism to reproduction, bone growth to self-preservation, and more. Take a few seconds to think of all the hormones you know…
Did you come up with Estrogen, Progesterone, and Testosterone? Perhaps a few of you even thought of Insulin.
If you got all four of those, great job! You scored above average. Would it shock you to know there are over 50 hormones in the human body? Holy Hormones, Honey! I’m willing to wager that most people don’t really know more that the few I’ve already listed off the top of their head, even though there are names you would certainly recognize once you heard them.
So what do these other hormones do for you, and how do they know what to do? Let’s take a look at one scenario:
Like any other typical evening you go out for a run, but tonight you decide to take a shortcut across the park. It’s later than usual, already far past twilight. A twig snaps somewhere to your left; you look, but you see nothing.
You keep running, a little faster now, and you’re growing increasingly nervous. Inside your brain, your hypothalamus receives the signal that you may be under threat and starts to kick in your fight-or-flight response.
It starts making Corticotropin-Releasing Hormone (CRH), which then funnels down the portal connecting the hypothalamus to the anterior pituitary gland and tells it to release Adrenocorticotropic Hormone (ACTH). The pituitary gland releases ACTH to the bloodstream, where it travels all the way to the adrenal glands (on top of each kidney) where it signals the release of a multitude of other hormones, including cortisol, epinephrine, and norepinephrine.
A chill runs up your spine as the blood is shunted to major organs who need it most, and goose bumps appear over your arms. Your heart rate increases and your blood starts pumping faster; your lungs take in more oxygen. Your pupils dilate so when you look over your shoulder in the dimly-lit park, you are able to take in more light and see better if there is someone behind you. All you can think about is getting to the other side, to safety, and every noise seems louder than before.
Finally the trees open up, streetlights flood your vision, and you take a deep breath. Your heartbeat slows back down and you start to relax. You’re home; you’re safe. And you probably got there in record time… Thanks to your hypothalamus and endocrine system. All of these physical changes that happen to help you escape the possible threat are due to the hormones controlling them.
In your body, as in life, communication is key. For the tens of trillions of cells within your body, of various shapes and sizes and specialties, much of that communication happens via your nervous system. For other parts, it happens via the endocrine system – a group of glands and organs that create a chemical cascade of events carried out by chemical messengers. These chemical messengers are your hormones.
However, if not all parts of your body are directly linked to the nervous system, how do they receive communication from the outside world and turn it into action? This is where your hypothalamus intercedes. It acts as the intermediary between the nervous system and the endocrine system, receiving nervous input and translating it to hormonal cues that are then sent to the pituitary gland. The hypothalamus is like the big boss at a company, giving out orders to the project manager (pituitary gland), who then gives orders to the rest of the employees (other glands) and instructs them on the job they need to perform (making hormones that your body needs to resolve a task).
Because of this role of stimulating hormone production in other glands, the pituitary gland is often referred to as the “Master Gland.” It does this by making hormones whose jobs are to travel to the other glands in your body and give them the message that they need to produce and secrete their specific hormones.
If you can’t name the parts of your endocrine system off the top of your head, no worries! Here is a list of the major players that help keep your body functioning properly, listed in order spatially, starting in your brain:
Look at that list of hormones on the right side! That’s just about half of the total hormones that can be found in your body. That list comprises the major hormones produced by the endocrine system. Some hormones have multiple forms, like estrogen which comes in four forms in your body: Estrone (E1), Estradiol (E2), Estriol (E3), Estetrol (E4). These forms differ in their chemical structure, so they each function slightly differently in the body.
Next time we will dig into these hormones more closely, explore how they work in your body and what makes one hormone different from another.