The sympathetic nervous system of this child is likely to kick in around now.
The sympathetic nervous system activates the "fight-or flight" response when we are in danger. If the sympathetic nervous system is not functioning properly, it can cause serious problems.
What is a sympathetic nervous?
Part of the autonomic nerve system, also known by the involuntary system, is the sympathetic nervous system. According to an American Journal of Pharmaceutical Education review, the autonomic nerve system controls important bodily functions like heart rate, blood pressure, pupil dilation and body temperature. Different types of nerve cells, known as neurons, are responsible for controlling different physical reactions. They direct the actions of skeletal muscle, cardiac muscle, and gland secretion. This system allows animals to quickly adjust their internal environment and respond to changes without needing to think about them.
The body's involuntary response to stressful or dangerous situations is controlled by the sympathetic nervous system. The body responds quickly to stressful situations by releasing hormones in a flash flood, increasing alertness and heart beat. The body's ability to breathe faster, delivering oxygen to the brain, and injecting glucose into the bloodstream, gives it an instant energy boost. Harvard Medical School says that this rapid response is often not noticed by people. A person might jump from the path a fallen tree to see if it is coming towards them.
Once the danger is gone or the tree has been cut down, the sympathetic nervous system does not depress the body. According to the Clinical Anatomy of the Brain Nerves published by Academic Press in 2014, the parasympathetic nervous systems, another component of the autonomic nerve system works to calm the body. This system helps to counter the fight-or flight response by encouraging the body to "rest, digest and digest". As the body settles into equilibrium or homeostasis, blood pressure, breathing rate, and hormone flow all return to their normal levels.
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Parasympathetic and sympathetic nervous systems work together to maintain normal body function and a baseline.
How does the sympathetic nervous system work?
According to a review published in BJA Education in 2016, structures in the brain and spinal cord support the function of sympathetic nervous systems. The spinal cord and cranial nervous systems send information to the brain via the receptors found in the internal organs of the abdomen and chest. The hypothalamus is a brain structure that regulates homeostasis. It receives signals from the body, and then tunes the activity in the autonomic nervous systems.
According to a review published in the journal Biological Psychiatry, this brain structure also collects information from higher brain areas, such as amygdala. The amygdala is often called the emotional brain. It pings the hypothalamus during stress.
Diagram of the sympathetic nervous systems. Image credit: Getty Images
The alert is then sent to the sympathetic nervous systems. This signal then reaches the adrenal glands which produce adrenaline, also known as epinephrine. This hormone causes the rapid heartbeat, profuse sweating and short breaths that are associated with stress. If the danger continues, the hypothalamus sends another message through the nerve system grapevine instructing the adrenal glands and hormone cortisol to continue the stress response.
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The spinal cord exits the sympathetic nervous system in the thoracolumbar area, or the middle to lower spine. The spinal cord is exited by sympathetic neurons, which extend in two columns either side. The neuronal tags then signal acetylcholine to a second group of nerve cells via the relay.
The second set of neurons, which carries the baton, extends to smooth muscle that performs involuntary movements, cardiac muscles, and glands throughout the body. Parasympathetic nervous systems communicate with many organs to maintain control of their activity.
What happens if it doesn't?
Each side of a wobbling balance has the sympathetic and parasympathetic nervous system. Each system is active and counteracts the actions of others. The body can achieve homeostasis if the opposing forces are balanced and operations go as normal. However, diseases can disturb the balance.
According to an article in the journal Autonomic Neuroscience, the sympathetic nervous system can become overactive in many diseases. These diseases include hypertension, chronic heart disease, and ischemic heart disease. Hypertension can be caused by an increase in sympathetic signaling. This increases blood pressure and improves tone of smooth muscles.
Hypertension (high blood pressure) can cause the sympathetic nervous system to become hyperactive. Image credit: Getty Images
Sympathetic dysfunction, which is not only associated with cardiovascular diseases, has also been linked to type II diabetes, kidney disease, obesity, metabolic syndrome, and even Parkinson's Disease.
Dr. Marina Emborg is the director of the Preclinical Parkinson's Research Program, University of Wisconsin-Madison. "While people think about Parkinson's disease only in terms of its motor symptoms," she said. The skin, eyes and heart are all affected by changes in sympathetic nervous activity.
Emborg explained to Live Science that Parkinson's patients may feel tired or fatigued, but in reality, heart problems can cause these symptoms.
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Parkinson's damage the sympathetic neurons that keep the body's levels of norepinephrine (epinephrine) and epinephrine (norrepinephrine) -- chemicals that tell your heart when to pump harder such as when you stand, exercise, or stand. Parkinson's patients can feel lightheaded when standing up, which can lead to a decrease in blood flow.
Forbes reported that sympathetic dysfunction is also responsible for mental health conditions like anxiety, depression, and chronic stress. The body's physiological stress response can provide a quick boost in mental focus and energy. The stress signals that whizz through the body can cause havoc if they are prolonged. The extra cortisol and epinephrine can cause blood vessel damage, high blood pressure, and a constant mental state of stress.
The fight-or-flight response is important, but you don't want to have it on constantly.
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