The human body is well adapted to deal with short-term stress, but it is not so well adapted for extended periods of stress. It was not until the 1970s that evidence of a physiological link between the mind, stress and body was documented.
One of the earliest studies involved rodents in labs at the University of Rochester, Medical Center, New York, US, This work led to the development of a new, hybrid field of study now known as psychoneuroimmunology, generally (and mercifully) shortened to “PNI”.
Using special fluorescent stains to trace nerves to various bodily locations, including bone marrow, lymph nodes, and the spleen, neurobiologist David Felten’s team discovered a network of nerves leading to blood vessels as well as cells of the immune system. The researchers also found nerves in the thymus and spleen terminating near clusters of lymphocytes, macrophages, and mast cells, all of which help control immune function.
Further research by the Rochester group has since documented the ways in which the brain sends signals to the immune system by finding receptors on the surface of immune-system cells that act as keyholes to accept chemical neurotransmitters released by the nervous system, as well as identifying new “keys,” neurotransmitters that would talk to cells of the immune system. A stimulus such as emotional stress can trigger the release of the nerve-fiber chemicals, which then tell the immune-system cells what to do. Dr. Felten says that all systems in the body are undoubtedly connected in this way – that there are countless “players”, as he calls them, in the human body, together creating a virtual telephone network of transmitters and receptors.
“Our grandmothers knew all along that our minds and bodies were connected, even if the scientific community didn’t,” says Dr. Felten. “We’ve simply provided irrefutable data that it’s true.”
But, let’s talk in more detail about how major systems respond to our worries and stress.
In this view, we see the organ pathway our food takes through the body. It starts in the mouth. There teeth masticate the food into small pieces and saliva provides several substances that initiate digestion. The esophagus brings the food into the stomach where pepsin and hydrochloric acid break down the long chains of proteins into smaller chains which are further digested in the small intestine (over 20 feet long and 1 inch in diameter in humans), which receives the partly digested food from the stomach. Here also the digestive process is completed, aided by the liver, the gall bladder and the pancreas. The liver has many functions, and provides bile to emulsify fats. The large intestine or colon (about 5 feet long and 2 inches in diameter in humans) serves to store undigested food and remove excess water, about 8 quarts per day, which is recycled back into the blood and tissue fluids. Bacteria, such as E. coli, reside in the colon and produce important vitamins which are absorbed into the blood stream. The terminal portion of the colon is the rectum leading to the anus at the surface of the body.
Scientific studies say that extreme stress can cause dry mouth, indigestion, nausea, and gas, and it stimulates the muscles of the intestines, possibly causing diarrhea or constipation.
In the human, the larynx and trachea in the throat connect with the bronchus, which in turn connects to each of the two lungs. Within the lung is a complex of folds whose surfaces are lined with capillaries, wherein the cells discharge CO2 and absorb O2. The diaphragm is the pump that enlarges the lung cavity to inhale fresh air and compresses it to exhale stale air. The muscles operating the diaphragm are controlled both voluntarily and involuntarily through a sensory organ in the brain which monitors the amount of CO2 in the blood stream.
Scientific studies show that at high-stress moments, we can find ourselves breathing faster, feeling short of breath, or even hyperventilating. Over the long term, this strain on the system can make you more susceptible to upper-respiratory infections.
The Circulatory System provides a means of bringing oxygen and nutrients to each cell of the body and removing CO2 and waste products from the cells. The heart is the muscular organ that moves the blood through the two-part system, containing about 65,000 miles of passages. In the pulmonary circuit, the blood flows from the heart in two arteries to the lungs, where CO2 is discharged and O2 is acquired, thence through four veins back to the heart. The systemic circuit serves the rest of the body. Red blood cells (humans have about 25 trillion) are unique in structure and function, in that they have no nucleus or mitochondria, but each cell has about 250 million molecules of hemoglobin, the protein that carries four iron atoms, each holding a molecule of oxygen during the trip from the lungs to the capillaries or a molecule of CO2 from the capillaries to the lungs.
The heart, about the size of a doubled-up fist and weighing less than 2 pounds, can operate 20-30 times a minute steadily without pause for over 100 years.. The amount of blood pumped by the heart in a lifetime would fill a train of tank cars 25 miles long!
Multiple studies have shown that sudden emotional stresses, especially anger, can cause narrowing of the arteries and elevate cholesterol levels, trigger heart attacks and stroke, upping your chances of arrhythmias, hard coronary heart disease (HCHD), myocardial infarction and even sudden death.
LYMPHATIC AND IMMUNE SYSTEMS
The immune system protects the body in two ways. The non-specific defenses include the inflammatory response to invasions of the skin, and the eating of foreign and dead self cells by phagocytes. The specific defenses are built around the lymphatic system. The bone marrow is the source of undifferentiated cells that become B and T white cells (In the bone marrow, stem cells specialize into immature lymphocytes, some of which mature into B cells to provide humoral immunity, and others which are carried by the blood to the thymus, where they mature into T cells to provide cell-mediated immunity. Both types are carried by the blood to the lymph nodes, spleen and other lymphatic organs.) through hormones secreted by the thymus and spleen. These two classes of specialized cells are stored in the lymph nodes where they are available to work on foreign cells and viruses brought to these centers by the lymph vessels, a network of tubes which serve all body tissues. The B and T cells are programmed to recognize literally millions of different invading bodies, each cell able to recognize one such type of invader. When the invader, in the lymph fluid brought to a lymph center, is recognized by a B or T cell, it quickly multiplies into the thousands to provide an attack force to eradicate the invader. “Memory” B or T cells are also generated. Whereas the attack cells last only a few weeks, the memory cells will last for years, even decades. The B cells operate on invaders in the interstitial fluid surrounding body cells, whereas the T cells kill invaders in the blood stream or lymph fluids. In spite of all this protective machinery the HIV virus is able to circumvent these defenses, as shown below.
Earlier research shows that short-term stress can slow wound healing, leaving us more susceptible to infection, and worsening skin conditions such as eczema, hives, and acne.
New research indicates that: 1) stress hormones increase the production of free radicals DNA -> damage and impaired immune function. 2) Stress hormones increase inflammation through the production of inflammatory proteins (cytokines) –>impair immune function and promote cancer growth. 3) Stress hormones directly impair immune cell function. 4) Stress hormones reduce the ability of abnormal cells to undergo apoptosis (cell death) and DNA repair, important self-regulating anticancer mechanisms. 5) Stress hormones stimulate the production of IGF-1 (insulin-like growth factor-1), VEGF (vascular endothelial growth factor) and other growth.
The Excretory System disposes of waste fluids, which are drained from the blood as it passes through the kidneys. From there the waste fluid passes through the ureters into temporary storage in the urinary bladder, from which it is voluntarily emptied through the urethra.
Studies show that stress can cause infections of our kidney and urethra, general kidney toxicity or kidney stones, and finally can cause kidney cancers and renal failure.
The Endocrine System is the collection of glands (pineal, pituitary, thyroid, thymus, adrenal) and other organs (pancreas, testis, ovary) that produce and secrete into the blood stream various hormones that regulate many activities of the body, such as digestion, metabolism, growth, reproduction, heart rate, and water balance.
Research shows that stress hormones trigger the liver to produce more blood sugar, to give us that kick of energy in the moment of perceived danger. Thus, chronic stress can elevate glucose levels and turn us into card-carrying diabetics.
The Reproductive Systems produce the male and female gametes (haploid cells), whose union in the female generate the zygote (diploid cell) from which a new organism will develop. These systems also include the organs which allow fertilization to occur.
Scientific studies show that stress often plays a role in erectile dysfunction and impotence.
It can lengthen or shorten a menstrual cycle also, stop it altogether, or make menstrual cycles more painful. High levels of stress make bacterial vaginosis (BV) more likely and, during pregnancy, may increase the chance of your baby’s developing asthma or allergies later in life.
The Nervous System works together with the endocrine system to coordinate body activities. The brain receives information from the sense organs (eyes, ears, nose, mouth, skin) and sends signals through the system of nerves branching out from the spinal cord. Rather than tubes to conduct fluids, such as the circulatory and lymph systems, a nerve channel is a chain of linked axons of nerve cells. There are millions of such signals every second, but a filtering network of neurons deep in the brain filters out all but a few hundred, and further filtering reduces that number to the few the conscious brain is concerned with.
Scientific studies show that when we’re stressed, the brain’s sympathetic nerves signal the adrenal glands to release a chemical variety pack, including epinephrine (aka adrenaline) and cortisol. Persistently high levels of these chemicals may impair memory and learning, and up your odds for depression.
MUSCULAR, SKELETAL AND INTEGUMENTARY SYSTEMS
The Muscular System consists of all skeletal muscles under voluntary control, which permit movement of the various parts of the body. Such muscles are attached to the bones or cartilage structures, and are controlled by nerve impulses. The heart muscles and the smooth muscles of blood vessels, intestines, and the like are considered to be parts of other systems.
The skeletal system is the system of interconnected bones and cartilage that support and protect the body. The integumentary system consists of the skin and its derivative hair and nails. Its major function is to protect the internal body parts from mechanical injury, infection, excessive heat or cold, and drying out.
Research shows that muscles tense to deal with what your body perceives as danger, and constantly tight muscles can cause headaches and migraines, vision problems, neck, shoulder, and back pain. Chronic stress may also increase your likelihood of developing osteoporosis.
References: “The Mind-BODY Connection: Granny Was Right, After All”, The Rochester Review, University of Rochester, Rochester, New York, US Krantz, D.S., Whittaker, K.S. & Sheps, D.S. (2011). “Psychosocial risk factors for coronary artery disease: Pathophysiologic mechanisms.” In Heart and Mind: Evolution of Cardiac Psychology . Washington, DC: APA. Stress: A Cause of Cancer?, by Lisa Hurt Kozarovich “Can Stress and Anxiety Cause Erectile Dysfunction?”, by Kimberly Holla “WONDERS OF GOD’S CREATION” by Dr. Herbert F. Mitchell “Reduce Stress to Prevent Headaches” by Joanne Barker, WebMD Feature “Immune System: Diseases, Disorders & Function”, by Kim Ann Zimmermann, LiveScience Contributor “Blood Urea Nitrogen (BUN)” by rnceus.com KIDNEY INFECTIONS AND RENAL FAILURE, by Lawrence Wilson, MD “Erectile Dysfunction and Stress Management”, Erectile Dysfunction Health Center