Peripheral Nervous System (Human Anatomy): Image, Functions, Diseases and Treatments

One of the two primary components of your body's nervous system is your peripheral nervous system (PNS). Most of your senses are fed information into your brain by your PNS. It carries the messages that let you contract your muscles. Your PNS also transmits signals to your brain, which it uses to regulate essential, automatic functions like breathing and heartbeat.

The peripheral nervous system (PNS) is the part of your nervous system that is not connected to your brain or spinal cord. It is responsible for both sending information from various parts of your body back to your brain and carrying out instructions from your brain to varying parts of your body.

The brain and spinal cord make up your central nervous system. Your peripheral nervous system is composed of nerves that move from your spinal cord and brain to your face and the remainder of your body.

All of your nerves are made up of clusters of nerve cells, each of which has long, fingerlike extensions called axons. In order to generate nerve fibres, nerve cells and accompanying axons twist and intertwine with one another. This is analogous to the twisting together of individual threads of fabric fibre to make a larger thread. A portion of the nerves in that cluster are responsible for bringing information into your brain, while the rest are responsible for expelling it.

• Sensory: These nerves are in charge of communicating information to the spinal cord and brain. Either they transmit information directly to your brain through the cranial nerves or they send information to the spinal nerves, which then flow into your spinal cord. Both of these options allow them to link directly to your brain. On the back of the spinal cord is where the connections for the sensory nerves are made to the spinal cord.
• Motor: These nerves transmit brain-issued instructions to various parts of your body. Your motor nerve connections are located on the front of the spinal cord, which means that these nerves are solely responsible for transmitting commands that cause muscle movement.
• Autonomic: These nerves regulate how your body's organs and systems operate automatically. Your autonomic nerves frequently include mixed nerve fibres, some of which transmit orders from your brain to their intended targets and others of which transmit feedback about the operation of an organ to your brain.

• Cranial nerves: There are 12 pairs of nerves that link directly to the brain, and 11 pairs of nerves that make up the peripheral nervous system (the second cranial nerve, which controls your vision, is part of your central nervous system). These 11 nerves contribute to your perceptions of smell, hearing, taste, and touch in the skin of your head, face, and neck. One of the 11 nerves, the vagus nerve, stretches from the neck to the colon and connects to all essential organs.
• Spinal nerves: There are 31 sets of nerves that connect to your spine around the same level as each vertebra.All of the nerves listed above divide out into even more finer nerves that travel to different parts of your body. You can find their last resting places in the tips of your fingers and toes or below the skin's surface.

Your autonomic and somatic subsystems are the two main parts of your peripheral nervous system.

• Autonomic: These are functions of the nervous system that your brain takes care of automatically, without you having to think about it.
• Somatic: These are functions that you control with your thoughts.
• Senses: The PNS plays an important role in relaying sensory data to the brain.
• Movement: All of the voluntary muscles in your body receive their instructions from your brain via your peripheral nerves.
• Unconscious processes: This is how critical processes in your brain are carried out, which do not depend on your conscious awareness of them. The beating of the heart and blood pressure are two examples of this.

Your brain functions like a supercomputer. Without input from outside sources, it is oblivious to the world outside your body. Similar to how a computer needs peripherals like a camera, microphone, or keyboard to get information from elsewhere, so does your brain. Your brain collects input about the outside environment through your peripheral nerve system. The majority of your peripheral nervous system enters or exits your spinal cord on its journey to the rest of your body.

Your cranial nerves are different from other peripheral nerves in that they link directly to your brain. These nerves transport messages from your nose, ears, mouth, and a variety of other organs. Your cranial nerves additionally provide you with a sense of touch in your face, head, and neck skin. Other peripheral nerves connect to each of your body's parts. Motor nerves enable you to move different areas of your body.

Your peripheral nerves, which branch throughout your body, provide command impulses from your brain to your muscles via the peripheral nerves. This allows you to move freely and perform a variety of actions, from simple ones such as scratching your nose to complex ones such as juggling.

Making sure that the systems that keep you alive function properly requires a portion of your brain to be active all the time. For your brain to control these functions, it needs the help of your peripheral nervous system. Your heart rate, breathing, blood pressure, and the way your gut breaks down food are all examples of these processes.

The peripheral nervous system aids your brain's self-care. As an example, your brain controls your heartbeat, ensuring that your heart circulates blood to your body as well as brain. Your brain would perish in minutes if there was no blood flow.

Neurons are the cells that send and relay signals through your nervous system, using both electrical and chemical signals. Each neuron consists of:

• Cell body: The primary component of the cell is known as the cell body.
• Axons: These are lengthy, appendage-like structures that stretch out from the cell body in all directions. There are many finger-like extensions at the end of the axon, and these are the locations in the neuron where the electrical signal is converted into a chemical signal. These connections are referred to as synapses, and they lead to adjacent nerve cells.
• Dendrites: These are tiny extensions that look like tree branches and are found on the body of the cell. Their name originates from a Latin term that meaning 'tree-like.' Chemical signals are sent from the synapses of neighbouring neurons to dendrites, which act as receivers for these signals.
• Myelin: It is a layer that is very thin and is made up of fatty chemical components. Myelin serves as a protective coating for the axon that extends from numerous neurons and is surrounded by myelin.
• Neuron connections are very complicated: with a single neuron's dendrites connecting to hundreds of other synapses. Some neurons are larger or shorter in length depending on where they are in your body and also what they perform.

Glial (pronounced glee-uhl) cells serve a variety of roles, including assisting in the development and maintenance of neurons while you are young and regulating how the neurons function throughout your whole life. In addition, they defend the nervous system from infection, regulate the chemical equilibrium of the nervous system, and produce the myelin covering on the axons of neurons. There are 10 times more glial cells than neurons in your neurological system.

• Diabetic nerve problems: Diabetes makes it more likely for a type of nerve damage called diabetic neuropathy to happen. Nerves all over the body can be hurt by having high blood sugar (glucose). Diabetes is especially likely to hurt nerves in the legs and feet.
• Guillain-Barre syndrome: People with Guillain-Barré syndrome (GBS) have sudden weakness in their muscles.Early warning signs frequently include changes in sensation or pain, typically in the back, and weakness in the hands and feet that frequently spreads to the arms and upper body.
• Acarpal tunnel syndrome: Ligaments and bones in the palm of the hand make a narrow passage. Soreness, tingling, and weakness in the hand and arm are just a few of the symptoms that may result from the compression of the median nerve.
• Thoracic outlet syndrome: Squeezing of blood vessels or nerves in the thoracic outlet (the region between the collarbone and the first rib) results in a condition known as thoracic outlet syndrome (TOS), which manifests as a group of symptoms.This might cause numbness in the hands and discomfort in the neck and shoulders.
• Complex regional pain syndrome: A subtype of chronic pain, often manifests itself first in the limbs, particularly the arms and legs. The start of chronic pain syndrome is often precipitated by traumatic experiences such as surgery, a stroke, or a heart attack. Other typical triggers include accidents or illnesses that damage nerves. The extent of the pain much beyond what could have been expected based on the initial harm.
• Brachial plexus injury: When these nerves are pulled, compressed, or torn from the spinal cord, a brachial plexus injury results. In contact sports like football, stingers and burners, which are minor brachial plexus injuries, are common.
• Charcot-Marie-Tooth disease: Charcot-Marie-Tooth disease: Nerve damage is a symptom of this genetic disorder. The majority of the injuries are to the limbs (peripheral nerves). Other names for Charcot-Marie-Tooth disease include hereditary motor and sensory neuropathy.
• Sjogren's syndrome: Sjogren's syndrome, the autoimmune condition characterised predominantly by these two symptoms, is known for its typical symptoms of dry eyes and dry mouth.Lupus: Your immune system of the body wrongly assaults healthy tissue and organs in lupus, an autoimmune condition (autoimmune disease). your joints, skin, organs, body fluids, central nervous system, heart, and lungs are just a few of the organs that may suffer damage from the inflammation brought on by lupus.
• Rheumatoid arthritis: Joint pain and inflammation may also affect other body areas in addition to the joints. The illness can have a negative impact on the skin, eyes, lungs, heart, and blood vessels, to name a few organs and systems.
• Lyme disease: Untreated Lyme disease symptoms can vary considerably from person to person and infection stage to infection stage. Fever, rashes, facial paralysis, and arthritis are all instances. Shingles: A painful rash is caused by shingles, a viral illness. Shingles can create a rash anywhere on the body. It usually appears as a single ring of blisters that wraps across your upper torso from side to side.
• Myasthenia gravis: When you have myasthenia gravis, the muscles under your voluntary control get weak and tire fast. The inefficiency of nerves and muscles to communicate adequately is at the base of the problem.
• Polyneuropathy: Polyneuropathy is a condition in which many peripheral nerves deteriorate simultaneously. Infections, toxins, drugs, malignancies, malnutrition, diabetes, autoimmune disorders, and other ailments can all cause peripheral nerves to malfunction.
• Chronic inflammatory demyelinating polyneuropathy (CIPD): Chronic inflammatory demyelinating polyneuropathy (CIDP), a nervous system disorder, is characterised by progressive limb weakness and decreased sensory function.
• Mononeuropathies: Long durations of typing may indicate the onset of carpal tunnel syndrome, which produces tingling or numbness in the hands and arms. Ulnar neuropathies are included under the broader category of mononeuropathies.
• Amyotrophic lateral sclerosis (ALS): A gradual weakening of skeletal, facial, and pulmonary muscles owing to injury to the motor neurons characterises Lou Gehrig's disease, the most severe type of neuromuscular illness.
• Radiculopathies: Your radiculopathy symptoms originate from a spinal nerve that has been compressed. Precisely, it develops when there is pressure or irritation on or close to a nerve root. Causes of small-fiber neuropathy: Small fibre sensory neuropathy (SFSN) is a disorder that mostly affects the smaller sensory cutaneous nerves. Most patients experience a gradual loss of feeling that starts in their feet and moves up their bodies. They have what is called in medicine as a length-dependent SFSN.
• Occupational neuropathies: Nerve damage, which may occur in the workplace or in sports like football owing to the stinger, often manifests itself in the form of weakness and numbness in the affected arm. Any illness affecting your central nervous system has the potential to manifest itself in your peripheral nerves. Even while they don't directly damage the peripheral nervous system, they may nevertheless cause problems with how it operates.

• EMG: Muscle and nerve function may be examined using electromyography (EMG), a diagnostic test (motor neurons). Electromyography (EMG) test results may shed light on nerve, muscle, or issues with nerve-to-muscle signal transmission dysfunction.
• NCV: A nerve conduction velocity (NCV) test may determine the velocity of your nerve impulses, which can help diagnose nerve injury or dysfunction. This method, also termed as a nerve conduction study, measures how quickly impulses flow through your peripheral nerves.
• SSEP: Neurologists are able to quantify the amount of time it takes for a stimulus to move from the site of stimulus (the wrist or ankle) to the site of detection down a nerve fibre (the scalp, the neck, or the back). By examining the SSEP pattern, the neurologist can determine how well these sensory nerves are working.
• Lumbar puncture (spinal tap): A small amount of spinal canal fluid will be removed from your lower back. The fluid is examined for a certain modification in order to make a Guillain-Barre syndrome diagnosis.
• Nerve biopsy: A sample of nerve tissue is taken, usually from a sensory nerve, and it is examined for anomalies.
• Skin biopsy: Your doctor could take away a small patch of skin to examine for a lack of nerve endings.

The types of damaged nerves affect the symptoms of peripheral nervous system issues. Your muscles are impacted by motor nerve damage by the following:

Weakness, Convulsions, tics, tremors, and spasms Wasting (shrinking of muscles) (shrinking of muscles), Inability to exert control over various body functions.

Damage to sensory nerves causes the following symptoms:

• Tingling or numbness (paresthesia): This sensation is similar to when an arm or leg nods off. Another way to convey this is that the afflicted area feels 'pins and needles'-like.
• Neuropathic pain: This is often referred to as nerve pain, and it frequently has a searing or piercing sensation surrounding the affected location. Sometimes the pain can be so bad that it prevents you from sleeping or carrying on with your daily activities. Some medical problems, including allodynia, can make even slight contact with a soft object, such as clothing or bedding, painful. The various bodily systems may be impacted.
• Circulatory system: Damage to autonomic nerves may prevent your body from regulating blood pressure.
• Digestive system: Depending on where the damaged area of your digestive system is, this may make it difficult to digest meals.
• Skin and temperature control: When it's hot, those who have autonomic nerve injury could find it difficult to feel comfortable. Additionally, they can either not sweat enough (anhidrosis) or oversweat (hyperhidrosis).

• Plasma exchange (plasmapheresis): Plasma, the liquid component of blood, is taken out and separated from the blood cells during this treatment. Plasma synthesis rises to compensate for the loss when the blood cells are reintroduced into the body. By eliminating the offending antibodies, plasmapheresis may aid in the immune system's attack on the peripheral nerves.
• Immunoglobulin therapy: In this process, the liquid component of blood known as plasma is taken out and separated from the blood cells. The body produces more plasma to replace the lost volume when the blood cells are reintroduced. Plasmapheresis may be able to aid by eliminating the immune system's attacking antibodies from the peripheral nerves.
• Endoscopic gastrostomy: A percutaneous endoscopic gastrostomy is the procedure used to introduce a feeding tube (PEG). The PEG tube, sometimes referred to as a feeding tube, enables the delivery of nutrients directly into the stomach. A PEG tube may be required if you have difficulty swallowing or are not consuming enough food through other methods.
• Nerve Decompression Surgery: Nerve decompression surgery, which is used to treat the discomfort and problems of DPN, may usually reverse the tingles and numbness associated with diabetic peripheral neuropathy (DPN) and prevent the need for amputation.
• Transcutaneous electrical nerve stimulation (TENS): Electrodes affixed to the skin can be used to provide a moderate electric current with a range of frequencies. A 30-minute TENS therapy once every day for about a month is advised.
• Physical therapy: Physical therapy helps persons with muscular weakness move more freely. You could also need to use a wheelchair, a walker, or crutches.

• Steroids for reducing inflammation of Peripheral nervous system: Inflammation brought on by immune-related malignancies such as basal cell carcinoma is treated with glucocorticoids. Prescriptions for cortisone-like drugs like prednisone, betamethasone, and dexamethasone are occasionally given to people who have certain types of myositis that manifest in different regions of the peripheral nervous system.
• Analgesics for pain in Peripheral nervous system: Corticosteroids are frequently only administered for short periods of time to reduce inflammation in order to avoid serious side effects such as muscular weakness, osteoporosis, high blood pressure, diabetes, and an increased vulnerability to infection.
• Muscle relaxants for stiffness in Peripheral nervous system: Muscle relaxants like metaxalone, methocarbamol, orphenadrine, or carisoprodol may be prescribed by a doctor to a patient.
• Antibiotics for infection in Peripheral nervous system: Antibiotics are a class of medication that are used to treat bacterial conditions that affect the pineal gland and the brain. Among the medications are Cephalosporin and Vancomycin.
• Nutritional supplements for reducing pain in Peripheral nervous system: They are used for the treatment of peripheral nervous system and promoting growth and development of neurons and muscles.
• Antivirals for treating infection of Peripheral nervous system: The antiviral medications oseltamivir or inhaled zanamivir are well-known for combating bacterial and fungal lung infections.

• Eat a balanced diet: Certain vitamin deficits, particularly vitamin B12, can have a serious impact on your neurological system. Other vitamins, particularly B6, are hazardous and induce peripheral neuropathy at large doses.
• Stay physically active and maintain a healthy weight: This is necessary to avoid injuries that might result in nerve damage. This, together with a balanced diet, can help to delay the development of Type 2 diabetes, which gradually affects your peripheral nerves.
• Wear safety equipment as needed: Accidents and injuries are frequent culprits in the development of nerve dysfunction. If you use safety gear when working or playing, you can avoid or at least mitigate many of these risks.
• Manage chronic conditions as recommended: If you have a chronic illness that might impact your peripheral nerves, notably Type 2 diabetes, it is critical that you treat it according to your healthcare provider's recommendations. This can either decrease the severity of the illness or postpone its progression.