Are you stressed? So what's the big deal isn't everyone?

Did you set an alarm this morning? Rush out of the house? Run into Traffic? Have a deadline you are rushing to meet?  A stressor is anything that knocks us out of homeostatic balance. A stressor could be skipping breakfast, a 101 degree summer day, anger, lack of sleep, too much work, trauma, allergies, infections, medical procedures, and excessive exercise (serious athletes are putting stress on their body and it is not healthy. If moderate exercise is good more is not better).  Side note here is that in humans we also can have anticipation and denial as stressors.

Stress is a daily occurrence.  It is normal and without stress response our bodies could not operate. The problem is not the small stressors we encounter each day but how we handle these stressors and the chronic stress we encounter.  Note: The biggest stressors in humans and primates are being low on the social ladder and not being able to change an undesirable situation.  The stress response from the Adrenal Glands is the body trying to reestablish homeostasis. It does this by secreting certain hormones, inhibiting others, activating particular parts of the nervous system. What is interesting is that no matter the stressor, whether we are running from an attacker, playing at the park on a hot afternoon, or stuck in traffic, we all turn on the same stress response. The core of our stress response is built around the fact that our muscles will need to work like crazy and we will need lots of energy right now not stored away for body rebuilding later (acute stress). 

Adrenal Glands have two parts the Cortex which is the outer part and the medulla, the middle. The Cortex produces hormones Cortisol and Corticosteroids whose primary functions are to increase blood sugar through gluconeogenesis; suppress the immune system; and aid in fat, protein and carbohydrate metabolism. This is so your body will have all the energy it needs to react fast to a stressful situation.

The medulla or middle produces epinephrine and nor epinephrine which increases heart rate, constricts blood vessels, dilates air passages and participates in the “fight or flight” part of the sympathetic nervous system. All of this is in response to the possibility that we will need our muscles to operate at peak performance. If the muscles are to work their best they will need glucose so the body releases it into the blood stream and if there is not enough in stored supply then fat and protein can be converted. Our digestion is stopped, so all energy can be focused on the muscles. Our heart rate goes up so it can pump blood to the muscles faster, the lungs dilate so more air can be brought in, our pupils dilate so we can see better at night, our blood pressure goes up so blood can get to the muscles rapidly. In addition the pituitary gland and hypothalamus release endorphins and enkephalins to block pain should we get into a fight and clot the blood should we be wounded.

So what happens if we don't have an acute stressor but instead a long term stressor such as a tough family relationship, a boss we can't stand, or just too much work? Obviously we can not sustain the elevated levels of epinephrine and nor epinephrine that we would see if someone started chasing us down the street so in prolonged stressful situations the Gluccocorticoids (specifically cortisol) comes to back up the sympathetic nervous system. So now you have the sympathetic nervous system in control and the Gluccocorticoids to help the body stay in stress longer term. The Gluccocorticoid families primary functions are to increase blood sugar through gluconeogenesis suppress the immune system, and aid in fat, protein and carbohydrate metabolism. It also decreases bone formation.

We know that elevated levels of Gluccocorticoids is a problem on several fronts.

• Gluccocorticoids will keep the blood sugar levels higher so the pancreas secretes more insulin and then blood sugar goes higher and sets up a vicious cycle. Also elevated levels of Gluccocorticoids counteract the release of insulin. Fat, protein, and carbohydrates are not stored but metabolized so the cells are not receiving adequate nutrition for regeneration.
• Elevated Gluccocorticoids weaken the immune system. The adrenal gland cortex produces cortisol and cortisone which are immune suppression anti-inflammatory steroids. Cortisol prevents proliferation of T-cells by rendering the interleukin-2 producer T-cells unresponsive to interleukin-1 (IL-1), and unable to produce the T-cell growth factor. Cortisol also reduces bone formation, causes calcium to leach from the bone, and reduces calcium absorption in the intestine. Cortisol also has been shown to shrink the thymus gland.
• Elevated levels of cortisol reduce reproduction function. In males the hormone system that stimulates sperm production and testosterone levels is inhibited. In females cortisol can shut down androgen production from the adrenal gland which is where where 5% of our estrogen comes from. Also in women stress can shrink fat cells telling the body there is not enough nutrition to support reproduction and finally ovulation is decreased.

The cortex of the adrenal glands produces the corticosteroids but the medulla of the adrenal glands produces Epinephrine and nor epinephrine under stress. These two hormones activate the sympathetic nervous system and are responsible for shutting down digestion, increasing heart rate, increasing blood flow, and increasing oxygen in take. In other words your heart is pounding, your breathing fast, your hands are sweating and shaking.

• Elevated levels of epinephrine and nor epinephrine are a problem for several reasons.The over stimulation of the sympathetic nervous system causes uneven wear on the bodies systems which leads to other hormones being disrupted, exhaustion, and fatigue of organs and hormone systems. This causes the desire for stimulants which cycles back into stimulating the adrenal glands.
• If the sympathetic nervous system is activated then digestion is slowed down. So the glucocorticoids are suppressing insulin and metabolizing your nutrient intake and now your digestion is slowed down so you may not be absorbing properly. You need more nutrients now to keep yourself healthy.
• If epinephrine and nor epinephrine are pumping through your body that means your heart is beating faster and working harder. Veins are constricted causing blood to return to the heart with more force. Your arteries are dilated so more blood can get to your muscles but a dramatic decrease in blood flow to non essential parts of the body like digestive tract and skin. If you have chronic stress than it stands to reason that you will have higher blood pressure or hypertension. Also though over time the blood returning to your heart with force will cause the left ventricle to thicken causing it to swell. This puts you at greater cardiac risk. And to make matters worse epinephrine makes circulating platelets more likely to clump together which can lead to atherosclerosis plaque. 

As you can see chronic stress is a major problem on the entire body. Tomorrow I will write about ways to improve your response to stress stimuli and ways to eliminate stress.