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PERIPHERAL NERVOUS SYSTEM
The peripheral nervous system or “PNS” informs the brain of the world around us and extends beyond the "CNS" central nervous system (the brain and spinal cord) to the limbs and organs. The PNS is not protected by bone structure as is the central nervous system, which leaves it exposed to toxins and mechanical injuries.
The peripheral nervous system is divided into two systems, the somatic nervous system and the autonomic nervous system.
The somatic nervous system is responsible for the coordination of the body and for receiving external stimuli. It is the system that regulates activities that are under conscious control.
The autonomic nervous system is made up of 12 pairs of cranial nerves that start at the base of the brain and 31 pairs of spinal nerves that leave the spinal cord through spaces between the vertebrae.
There are three divisions of the autonomic nervous system, the sympathetic division, parasympathetic division, and enteric division. The sympathetic nervous system responds to impending danger or stress, and is responsible for the increase of our heartbeat and blood pressure. The parasympathetic nervous system is evident when a person is resting and/or feeling relaxed, it is also responsible for the constriction of the pupil, the slowing of the heart, the dilation of the blood vessels and the stimulation of the digestive and genitourinary systems. The purpose of the enteric nervous system is to manage our digestion, from the esophagus to the stomach including the small intestine and colon.
Nerve messages that travel to the brain are called sensory because the bring sensations such as touch, taste or sight, while those travelling from the brain are called motor because they initiate movement. Some cranial nerves are mixed – they are two-way lines that allow both types of signals to pass. The branial nerves mainly serve the head and neck. The only one that travels further into the body is the vagus nerve, this is an important part of the autonomic not the peripheral nervous system.
All 31 pairs of spinal nerves are mixed carrying both sensory messages to and motor signals from the brain. The back of the spinal cord is dedicated to sensory impulses travelling upwards whereas the front deals with the motor impulses moving down. There are twelve pairs of thoracic nerves serving the intercostal muscles and some of the back and abdomen; there are five pairs of sacral nerves which leave through openings in the sacrum and four pairs of coccygeal nerves serving the buttocks, genital region, legs and feet.
Massaging essential oils into our bodies can be a good antidote to stress as can aromatic baths and inhalation which can give a feeling of good health and wellbeing.
By: Lesley-Ann Sales - Utah, United States |
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