Nervous System : Detailed Explanation


What is the Nervous System?

The nervous system is the part of an animal's or human's body that coordinates its actions and transmits signals to and from different parts of its body. The nervous system detects environmental changes that impact the organism, then it works in tandem with the endocrine system to respond to these changes. Nervous tissue first originated in wormlike animals about 550 to 600 million years ago. In vertebrates it consists of two main parts, the central nervous system (CNS) and the peripheral nervous system (PNS).

The nervous system is responsible for the control of the body. It consists of the brain, the spinal cord, and the nerves. The nervous system is responsible for the control of the body. It consists of the brain, the spinal cord, and the nerves.

Nerves of the human body

The human nervous system is an amazingly complex network of nerve cells (neurons) that carry messages back and forth between the brain and spinal cord and the rest of the body. The nervous system is made up of the central nervous system (CNS), which includes the brain and spinal cord, and the peripheral nervous system (PNS), which includes all the nerves that branch out from the brain and spinal cord.  The autonomic nervous system (ANS) is a part of the PNS that controls the body's involuntary functions, such as heart rate, blood pressure, digestion, and respiration.


  • Structure of the nervous system

  • Development of the nervous system

  • The spinal cord or medulla spinalis

  • The brain or encephalon

  • The hindbrain or rhombencephalon

  • The midbrain or mesencephalon

  • The forebrain or prosencephalon

  • Composition and central connections of the spinal nerves

  • Pathways from the brain to the spinal cord

  • The meninges of the brain and medulla spinalis

  • The cerebrospinal fluid

  • The cranial nerves

  • The olfactory nerves

  • The optic nerve

  • The oculomotor nerve

  • The trochlear nerve

  • The trigeminal nerve

  • The abducens nerve

  • The facial nerve

  • The vestibulocochlear nerve

  • The glossopharyngeal nerve

  • The vagus nerve

  • The accessory nerve

  • The hypoglossal nerve

  • The spinal nerves

  • The posterior divisions

  • The anterior divisions

  • The thoracic nerves

  • The lumbosacral plexus

  • The sacral and coccygeal nerves

  • The sympathetic nerves

  • The cephalic portion of the sympathetic system

  • The cervical portion of the sympathetic system

  • The thoracic portion of the sympathetic system

  • The abdominal portion of the sympathetic system

  • The pelvic portion of the sympathetic system

  • The great plexuses of the sympathetic system

Nervous system Structure

The human nervous system comprises the central nervous system (CNS) and the peripheral nervous system (PNS). The CNS includes the brain and the spinal cord. The PNS consists of all of the nerves that branch out from the brain and spinal cord. Together, the CNS and PNS control all voluntary and involuntary actions of the body.

The anxious device has two fundamental parts. Each element includes billions of cells called neurons, or nerve cells. These unique cells send and get hold of electric indicators through your frame to tell it what to do.

The fundamental components of the anxious gadget are:


  • Central nervous system (CNS): Your mind and spinal twine make up your CNS. Your brain uses your nerves to send messages to the relaxation of your body. Each nerve has a protective outer layer known as myelin. Myelin insulates the nerve and facilitates the messages getting through.

  • Peripheral fearful system: Your peripheral anxious machine consists of many nerves that department out from your CNS all over your frame. This machine relays facts from your brain and spinal wire for your organs, arms, legs, palms and feet. Your peripheral worried machine includes your:

  • Somatic frightened gadget, which courses your voluntary actions.

  • Autonomic anxious gadget, which controls the sports you do without considering them.

Sensory system

The sensory apprehensive system is a part of the fearful device liable for processing sensory statistics. A sensory gadget includes sensory neurons (together with the sensory receptor cells), neural pathways, and parts of the mind involved in sensory perception. Commonly identified sensory systems are those for imaginative and prescient, listening to, touch, taste, smell, and balance. Senses are transducers from the bodily international to the realm of the thoughts wherein human beings interpret the facts, growing their belief of the world around them.

The receptive subject is the vicinity of the frame or environment to which a receptor organ and receptor cells respond. For example, the part of the sector a watch can see is its receptive area; the light that each rod or cone can see is its receptive field. Receptive fields have been diagnosed for the visible device, auditory machine and somatosensory machine.

  • Sensory neuron

  • Perception

  • Visual system

  • Auditory system

  • Somatosensory system

  • Vestibular system

  • Olfactory system

  • Taste

  • Pain

Components of the nervous system

  • Neuron

  • Interneuron

  • Ganglion (PNS) vs Nucleus (neuroanatomy) (CNS) except basal ganglia (CNS)

  • Nerve(PNS) vs Tract (neuroanatomy) (CNS)

  • White matter (more myelinated) vs Grey matter

Glial cells

  • Microglia

  • Astrocyte

  • Oligodendrocyte (CNS) vs Schwann cell (PNS)


A neuron is an electrically excitable cell that processes and transmits information through electrochemical signaling. Neurons are the core components of the nervous system, which includes the brain, spinal cord, and peripheral nerves. Basic types of neurons include sensory neurons, motor neurons, and interneurons. Sensory neurons send signals from the body's periphery to the central nervous system.

  • Soma

  • Axon

  • Myelin

  • Dendrite

  • Dendritic spine

Biological neural network

A neural network is a system of simple elements called neurons, which receive input, change their internal state (activation) according to that input, and produce output depending on the input and activation.

A biological neural network is a network of interconnected neurons that process information through electrical and chemical signals. These signals between neurons occur via synapses, specialized connections with other cells. Neurons can connect to each other to form neural networks, allowing information to be passed between neurons. Biological neural networks have been found in a variety of species, including mollusks, insects, fish, and mammals.

  • Central pattern generator

  • Reflex arc

  • Neural oscillations

  • Neural network

Biological neural networks have been studied extensively and the brain has proven to be the inspiration for many artificial neural networks. Brain-inspired artificial neural networks have the ability to learn and generalize like the brain, making them powerful learning machines. Neural networks are composed of a large number of interconnected processing nodes, or neurons, that can communicate with each other via synapses. Neural networks are very good at learning from data and have been used for a variety of tasks, including pattern recognition, classification, prediction, and control.

Nervous System function

The nervous system is a complex network of specialized cells, tissues, and organs that play a crucial role in transmitting signals and coordinating various bodily functions. Its primary function is to regulate and control both voluntary and involuntary actions throughout the body. The nervous system is divided into two main parts: the central nervous system (CNS) and the peripheral nervous system (PNS).

  1. Central Nervous System (CNS): This consists of the brain and the spinal cord. The brain serves as the command center of the body, responsible for processing sensory information, making decisions, and initiating responses. The spinal cord acts as a relay between the brain and the rest of the body, transmitting signals to and from the brain.

  2. Peripheral Nervous System (PNS): This network connects the CNS to the rest of the body. It is further divided into the somatic nervous system and the autonomic nervous system.

  • Somatic Nervous System: This controls voluntary movements and transmits sensory information from the sensory organs to the CNS. It allows you to consciously control actions like walking, talking, and moving your limbs.

  • Autonomic Nervous System: This controls involuntary functions that are essential for maintaining homeostasis, such as heart rate, digestion, breathing, and glandular secretion. The autonomic nervous system is further divided into the sympathetic and parasympathetic divisions, which often work in opposition to regulate different bodily functions. For example, the sympathetic division triggers the "fight or flight" response during stress or danger, while the parasympathetic division promotes the "rest and digest" response when the body is at rest.

The nervous system carries out its functions through the transmission of signals called nerve impulses or action potentials. These impulses travel along specialized cells known as neurons. Neurons are the functional units of the nervous system, and they communicate with each other and with other cells, such as muscle cells and glands, through synapses.

In summary, the nervous system plays a fundamental role in controlling and coordinating various bodily activities, ranging from conscious movements to automatic physiological processes, ensuring that the body functions properly and responds appropriately to changes in its environment.

Nervous System Problems

Nervous system problems can encompass a wide range of disorders and conditions that affect the central nervous system (brain and spinal cord) and the peripheral nervous system (nerves outside the brain and spinal cord). Here are some common nervous system problems:

  • Neurodegenerative Disorders:

  • Stroke and Vascular Disorders:

  • Epilepsy and Seizure Disorders:

    • Epilepsy

    • Absence seizures

    • Grand mal seizures

    • Focal seizures

  • Multiple Sclerosis (MS): An autoimmune disorder where the immune system attacks the protective covering of nerve fibers, causing communication problems between the brain and the rest of the body.

  • Peripheral Neuropathy: Damage to peripheral nerves that leads to symptoms like tingling, numbness, weakness, and pain, often in the hands and feet.

  • Migraines: Severe headaches often accompanied by light sensitivity, nausea, and visual disturbances.

  • Neuromuscular Disorders:

    • Muscular dystrophy

    • Myasthenia gravis

    • Charcot-Marie-Tooth disease

  • Spinal Cord Injuries: Trauma to the spinal cord can lead to paralysis and sensory loss below the injury site.

  • Neuralgia: Intense, stabbing pain along a damaged nerve.

  • Guillain-BarrĂ© Syndrome: An autoimmune disorder where the immune system attacks the peripheral nerves, leading to weakness, tingling, and even paralysis.

  • Cerebral Palsy: A group of disorders affecting movement and muscle tone, often caused by damage to the developing brain.

  • Traumatic Brain Injury (TBI): Damage to the brain from head trauma, leading to cognitive, emotional, and physical impairments.

  • Neurodevelopmental Disorders:

  • Brain Tumors: Abnormal growths of cells within the brain, which can be benign or malignant.

  • Degenerative Disc Disease: Breakdown of intervertebral discs in the spine, causing pain and other symptoms.

  • Restless Legs Syndrome: A condition characterized by an irresistible urge to move the legs, often accompanied by uncomfortable sensations.

  • Central Pain Syndrome: Chronic pain caused by damage to the central nervous system.

It's important to note that the nervous system is complex, and the symptoms and treatment options for these disorders can vary widely. If you suspect you or someone else is experiencing a nervous system problem, it's recommended to seek medical attention from a qualified healthcare professional.

How is it diagnosed in the Nervous System?

Diagnosing conditions or disorders in the nervous system typically involves a combination of medical history assessment, clinical examination, and various diagnostic tests. The specific diagnostic process can vary based on the suspected condition, but here are some common steps and techniques involved:

  • Medical History and Physical Examination: The first step is often to gather detailed information about the patient's symptoms, medical history, family history, and any relevant factors that might contribute to the neurological issue. A thorough physical examination is also conducted to assess motor skills, reflexes, sensory perception, and overall neurological function.

  • Neurological Examination: A specialized neurological examination is performed by a neurologist. This involves evaluating the patient's mental status, cranial nerves, motor function, sensory function, reflexes, coordination, and gait.

  • Imaging Techniques:

    • MRI (Magnetic Resonance Imaging): This technique provides detailed images of the brain and spinal cord, helping to visualize structures and identify abnormalities such as tumors, lesions, or structural anomalies.

    • CT (Computed Tomography) Scan: CT scans can offer detailed cross-sectional images of the brain and spine, assisting in detecting tumors, bleeding, or other structural issues.

    • PET (Positron Emission Tomography) Scan: PET scans can show the metabolic activity of the brain and help identify areas of abnormal function, often used in cases of epilepsy or certain brain disorders.

    • SPECT (Single Photon Emission Computed Tomography) Scan: Similar to PET, SPECT scans can reveal brain activity and blood flow patterns, aiding in diagnosing certain neurological conditions.

  • Electrodiagnostic Tests:

    • Electroencephalography (EEG): EEG measures the electrical activity of the brain and is particularly useful in diagnosing epilepsy, sleep disorders, and brain function abnormalities.

    • Electromyography (EMG) and Nerve Conduction Studies (NCS): These tests assess the electrical activity of muscles and nerves, helping diagnose conditions like neuropathies, myopathies, and neuromuscular junction disorders.

  • Cerebrospinal Fluid (CSF) Analysis: In some cases, a lumbar puncture (spinal tap) may be performed to collect and analyze cerebrospinal fluid. This can help diagnose infections, inflammation, and certain neurological disorders such as multiple sclerosis.

  • Genetic Testing: For hereditary neurological conditions, genetic testing may be used to identify specific genetic mutations that are associated with the disorder.

  • Biopsy: In cases where a tumor or lesion is suspected, a biopsy may be performed to analyze a tissue sample and determine its nature.

  • Neuropsychological Testing: These tests assess cognitive and psychological functions to identify any deficits or changes in brain function, commonly used for conditions like dementia or traumatic brain injury.

  • Functional Assessments: These assessments evaluate specific functions, such as cognitive abilities, movement, and sensory perception, to determine the impact of a neurological disorder on a person's daily life.

It's important to note that the diagnostic process can be complex and may involve a combination of these techniques. Neurologists and other medical professionals use their expertise to interpret the results and arrive at an accurate diagnosis, which then guides the treatment plan for the patient.

Maintaining a healthy Nervous System

Maintaining a healthy nervous system is crucial for overall well-being, as it plays a central role in controlling and coordinating various bodily functions. Here are some tips for maintaining a healthy nervous system:

  • Balanced Diet: A well-balanced diet rich in vitamins, minerals, antioxidants, and essential fatty acids is important for supporting nerve health. Foods like leafy greens, fruits, whole grains, nuts, seeds, and fatty fish can provide the necessary nutrients.

  • Hydration: Staying adequately hydrated helps in maintaining proper nerve function. Water is essential for transmitting nerve signals and supporting the overall cellular processes of the nervous system.

  • Regular Exercise: Physical activity promotes blood circulation and oxygen delivery to nerve cells, aiding in their proper function and maintenance. Cardiovascular exercises, strength training, and yoga can be beneficial.

  • Adequate Sleep: Sleep is crucial for nerve regeneration, memory consolidation, and overall brain health. Aim for 7-9 hours of quality sleep each night to support nervous system recovery.

  • Stress Management: Chronic stress can negatively impact the nervous system. Practicing relaxation techniques such as meditation, deep breathing, mindfulness, and hobbies can help reduce stress and promote nervous system health.

  • Limit Toxins: Exposure to environmental toxins and pollutants can harm nerve cells. Minimize exposure to chemicals, heavy metals, and other harmful substances whenever possible.

  • Avoid Harmful Habits: Smoking, excessive alcohol consumption, and illicit drug use can damage nerves and impair nervous system function. Quitting or reducing these habits can promote nerve health.

  • Stay Active Mentally: Engaging in activities that challenge your brain, such as puzzles, reading, learning new skills, and social interactions, can help maintain cognitive function and support overall nervous system health.

  • Maintain a Healthy Weight: Being overweight or underweight can affect nerve function. Strive for a healthy weight through a balanced diet and regular exercise.

  • Regular Check-ups: Periodic health check-ups can help identify any potential issues early on. Conditions like diabetes, vitamin deficiencies, and autoimmune disorders can impact nerve health, and addressing these conditions promptly can prevent further damage.

  • Stay Hygiene-conscious: Practicing good hygiene and taking steps to prevent infections can prevent conditions that might lead to nerve damage, such as certain viral infections.

  • Stay Hydrated: Dehydration can affect nerve function and lead to various health issues. Make sure to drink enough water throughout the day to stay properly hydrated.

  • Nutritional Supplements: In some cases, your healthcare provider might recommend specific supplements, such as B vitamins, omega-3 fatty acids, or antioxidants, to support nerve health. Consult a healthcare professional before taking any supplements.

Remember that individual needs may vary, so it's important to consult with a healthcare professional before making significant changes to your lifestyle or starting any new health regimen, especially if you have preexisting health conditions or concerns about your nervous system.

Next Post Previous Post