In your body there are over 50 different of hormones, each of them with specific roles in various tissues. Last time we talked about the endocrine system, the series of organs and glands that produce your hormones through a cascade of reactions, resulting in maintaining your body’s homeostasis and keeping it body functioning properly. So what do some these individual hormones do specifically?
Let’s revisit the scenario of your run through the dimly lit park again, but we’ll take a look at the chain of events in the body more closely.
When you experience a kind of stressor – be it a perception of threat, or sudden bright lights or loud noises – one of your body’s reaction is to set off this hormone cascade starting in the hypothalamus to prepare you to run away or prepare your body to fight to defend yourself if necessary. This integration of physical and psychosocial inputs from the outside world and your body’s hormonal responses to them are what allow you to adapt and survive.
This hypothalamic-pituitary-adrenal relationship is the backbone of the neuroendocrine response to stresses; in journals and medical jargon you will see it referred to as the “HPA axis.” It affects the major systems in your body including metabolic, cardiovascular, immune, central nervous, and reproductive systems.
Epinephrine and norepinephrine are what are called catecholamines (CAT-EH-KHOL-A-MEENS), which means they are neurotransmitters derived from the amino acid Tyrosine. Tyrosine and its precursor Phenylalanine (FEE-NIL-AL-UH-NEEN) are two of the nine Essential Amino Acids that your body cannot make on its own, it must be eaten in your diet. So be sure to include in your diet foods such as cheese and dairy, chicken and eggs, pork, fish, and lamb which are all very high in tyrosine. For those who are vegetarians, don’t worry! Nuts, seeds, beans, bananas, avocados, and whole grains are also high in Tyrosine.
Just as an aside, Dopamine is another catecholamine. So if you need a Dopamine boost, look to your diet as well!
Let’s look at another major part of the fight-or-flight response that occurs in the Adrenal Glands.
When you first wake up in the morning your body starts producing cortisol – the stress hormone. Within the first 20-30 minutes after waking, your cortisol levels will be already 50% higher than they were. This is your body’s natural jolt of energy, like its own self-made pot of coffee coursing through your veins, just without the jitters. These levels peak around mid-morning and taper off the rest of the day.
However, during times of stress there is an additional spike of cortisol that gives your muscles an energy boost they may need. Cortisol can also help fight inflammation and regulate blood pressure.
A study has shown it has even been found to help in memory recall. We hear people say that they “thrive under pressure” – it’s the resonating mantra of the procrastinators! I myself was one of those who found myself way more capable of remembering appointments, information, and to-do’s when I had an overloaded schedule than when I only have a few things I needed to accomplish. This may be because cortisol seems to help facilitate memory and recall or planning tasks, or events that have a sequential component.
So if you find yourself a little stressed out, don’t fret (too much). Just embrace it and remember your cortisol is there to help you out.
However, if there is chronic stress, this can lead to too much cortisol in the body and may lead to adrenal complications or even insulin resistance if it continues for too long.
Even with hormones, sometimes too much of a good thing isn’t good for long. Again, like that pot of coffee – the caffeine is great for the morning pick-me-up and the cure-all for that afternoon slump, but if you take more than a couple No-Doze, you just might find yourself with an inability to focus and a case of the shakes. (Yes, there is a story behind that from my college days).
Notice in the two graphics that the hormone ACTH signals the synthesis and release of Epinephrine and Norepinephrine from the Adrenal Medulla (remember that’s the inner part of the adrenal gland); this is the same molecule that signals the synthesis and release of Cortisol from the Adrenal Cortex (the outer part of the adrenal gland). This molecule is also able, to some degree, to signal the synthesis and secretion of Aldosterone from the adrenal cortex as well.
Even though it comes from the adrenal cortex, an enzyme that comes from your kidneys actually is the main regulator your Aldosterone levels! This hormone system is called RAAS – Renin-Angiotensin-Aldosterone System and involved enzymes from your kidneys, liver, and lungs. It kicks into gear when your blood pressure is low and when you are in stressful situations. It really is amazing how your body can work together to keep you functioning properly. In times of stress, your whole body is affected so it seems logical that several groups pitch-in to make it all come together.
In comparison to cortisol, which follows the circadian clock, Aldosterone tends to follow your sleep patterns; it is elevated while you sleep, being at its highest level in the morning when you wake. Seems logical that times when you really need regulation and water retention is during time when you can neither eat nor drink nor go to the bathroom.
Aldosterone is critical in your body as it is involved in regulating the balance of salts (mainly sodium and potassium) and water in your body. This balance is crucial for blood pressure – when there is more fluid in your blood, there is more pressure in your blood vessels; when there is too little, your blood pressure drops. In response to this drop in blood pressure, your body sends a signal that it needs to get the pressure back up – it does this in a bilateral fashion, by targeting both water-retention and constriction of your blood vessels.
The kidney enzyme Renin starts a cascade that actually releases more that just Aldosterone. Along with it, Vasopressin (a water-retention hormone released from your posterior pituitary), Epinephrine, and Norepinephrine are released. So all together, this pathway utilizes FOUR hormones in order to get your blood pressure back to normal.
But again, the body needs these things to be in a balance. It can’t be firing this system on all cylinders all the time, keeping your blood pressure high. These hormones have receptors in your heart as well and a chronic overabundance can negatively impact your heart health, potentially leading to heart failure.
So now you can start to get a better idea of just how interwoven the mechanisms in your body are, working together in synergy to take care of you. Often things in your body works more like a web of events – like how one hormone or one enzyme can result in the production of several other hormones or multiple physiological effects. Also, we have touched on how your diet can impact your hormones and your body in ways that aren’t just about the pounds on the scale.
Your body is an amazing and intricate machine! So take care of your body and your body will take care of you, or perhaps more aptly, your hormones will see to it that your body is well taken care of. Take a moment every once in awhile to appreciate how hard they work for you!