Advanced searches left 3/3
Search only database of 8 mil and more summaries

Functions Of The Nervous System

Summarized by PlexPage
Last Updated: 02 July 2021

* If you want to update the article please login/register

General | Latest Info

The nervous system is a complex collection of nerves and specialized cells know as neurons that transmit signals between different parts of the body. It is essentially the body's electrical wiring. Structurally, nervous system has two components: central nervous system and the peripheral nervous system. According to the National Institutes of Health, central nervous system is made up of the brain, spinal cord and nerves. The Peripheral Nervous system consists of sensory neurons, ganglia and nerves that connect to one another and to the central nervous system. Functionally, nervous system has two main subdivisions: somatic, or voluntary, component; and autonomic, or involuntary, component. The Autonomic Nervous system regulates certain body process, such as blood pressure and rate of breathing, that work without conscious effort, according to Merck Manuals. The somatic system consists of nerves that connect the brain and spinal cord with muscles and sensory receptors in the skin.

* Please keep in mind that all text is machine-generated, we do not bear any responsibility, and you should always get advice from professionals before taking any actions.

* Please keep in mind that all text is machine-generated, we do not bear any responsibility, and you should always get advice from professionals before taking any actions

Description of the nervous system

Nerves are cylindrical bundles of fibers that start at the brain and central cord and branch out to every other part of the body, according to University of Michigan Medical School. Neurons send signals to other cells through thin fibers called axons, which cause chemicals know as neurotransmitters to be released at junctions called synapses, NIH note. There are over 100 trillion neural connections in the average human brain, though number and location can vary. For example, new study published in January 2018 in the journal Proceedings of National Academy of Sciences found that out of 160 participants study, brains of highly creative people have more connections among three specific regions of the brain than less creative thinkers. You have these three different systems that are all located in different parts of the brain, but they are all co - activate at once, says lead study author Roger Beaty, postdoctoral fellow studying cognitive neuroscience at Harvard University. People who are better able to co - activate them with more - creative responses. The Synapse gives command to the cell and the entire communication process typically takes only a fraction of a millisecond. Signals travel along alpha motor neuron in the spinal cord 268 mph; fastest transmission in the human body, according to Discover magazine. Sensory neurons react to physical stimuli such as light, sound and touch and send feedback to the central nervous system about the body's surrounding environment, according to the American Psychological Association. Motor neurons, located in the central nervous system or in peripheral ganglia, transmit signals to activate muscles or glands. Glial cells, derive from the Greek word for glue, are specialized cells that support, protect or nourish nerve cells, according to Oregon Institute of Health and Science University. The brain's connections and thinking ability have grown over thousands of years of evolution. For example, virus bind its genetic code to the genome of four - limbed animals, and the code can still be found in human brains today, according to two papers published in the January 2018 journal Cell. This code packages up genetic information and sends it from nerve cells to other nearby nerve cells, very important process in the brain.

* Please keep in mind that all text is machine-generated, we do not bear any responsibility, and you should always get advice from professionals before taking any actions.

* Please keep in mind that all text is machine-generated, we do not bear any responsibility, and you should always get advice from professionals before taking any actions

Diagnosing nervous system conditions

There are a number of tests and procedures to diagnose conditions involving the nervous system. In addition to traditional X - ray, specialized X - ray called fluoroscopy examines the body in motion, such as blood flowing through arteries, according to NIH. Other standard neurological exams include MRI, CT scan, and electroencephalogram, which record the brain's continuous electrical activity. Positron emission tomography is a procedure that measures cell or tissue metabolism and brain activity to detect tumors or diseased tissue or tumors, NIH note. The Spinal tap places a needle into the spinal canal to drain a small amount of cerebral spinal fluid that is tested for infection or other abnormalities, according to NIH.

* Please keep in mind that all text is machine-generated, we do not bear any responsibility, and you should always get advice from professionals before taking any actions.

* Please keep in mind that all text is machine-generated, we do not bear any responsibility, and you should always get advice from professionals before taking any actions

Diseases of the nervous system

A number of different medical conditions can affect the nervous system, including: blood vessel disorders in the brain, including arteriovenous malformations and cerebral aneurysms Tumors, benign and malignant degenerative diseases, including Alzheimer's disease and Parkinson's disease. Disorders of pituitary gland Epilepsy Headaches, including migraines head injuries such as concussions and brain trauma Movement Disorders, such as tremors and Parkinson disease Demyelinating diseases such as Multiple sclerosis Neuro - ophthalmologic diseases, which are vision problems that result from damage to optic Nerve or its connections to brain Peripheral Nerve diseases, which affect nerves that carry information to and from brain and Spinal cord Mental Disorders, such as schizophrenia Spine Disorders Infections, such as meningitis Stroke neurologists and other neuroscience specialists use special tests and imaging techniques to see how nerves and brain are working. In addition to blood and urine tests, tests to diagnose nervous system diseases may include: compute tomography lumbar puncture to check for infection of spinal cord and brain, or to measure pressure of cerebro - Spinal fluid magnetic resonance imaging or magnetic resonance angiography electroencephalography to look at brain activity Electromyography to test Nerve and muscle function Electronystagmography to check for abnormal eye movements, which can be sign of brain disorder evoke potentials, which look at how brain respond to sounds, sight, and touch Magnetoencephalography myelogram of Spine to diagnose Nerve injury Nerve conduction velocity test Neurocognitive testing polysomnogram to see how brain react during sleep Single photon emission compute tomography and positron emission tomography scan to look at brain metabolic activity Biopsy of brain, Nerve, skin, or muscle to determine if there's problem with nervous system neuroradiology is branch of neuroscience medicine that focus on diagnosing and treating nervous system problems. Interventional neuroradiology involves inserting tiny, flexible tubes called catheters into blood vessels leading to the brain. This allows doctors to treat blood vessel disorders that can affect the nervous system, such as stroke. Balloon angioplasty and stenting of carotid or vertebral artery Endovascular embolization and coiling to treat cerebral aneurysms Intra - arterial therapy for Stroke Radiation oncology of brain and Spine Needle biopsies, Spine and soft tissues Kyphoplasty and vertebroplasty to treat vertebral fractures open or traditional neurosurgery may be needed in some cases to treat problems in brain and surrounding structures. This is more invasive surgery that requires surgeon to make an opening, called craniotomy, in the skull. Microsurgery allows surgeons to work on very small structures in the brain using microscope and very small, precise instruments. Stereotactic radiosurgery may be needed for certain types of nervous system disorders. This is a form of radiation therapy that focuses high - power x - rays on small areas of the body, thereby avoiding damage to surrounding brain tissue.


Overview

The Nervous system is a complex, highly specialized network. It organize, explains, and directs interactions between you and the world around you. The nervous system controls: sight, hearing, taste, smell, and feeling. Voluntary and involuntary functions, such as movement, balance, and coordination. Nervous systems also regulate actions of most other body systems, such as blood flow and blood pressure. Ability to think and reason. The nervous system allows you to be conscious and have thoughts, memories, and language. The nervous system is divided into brain and spinal cord and nerve cells that control voluntary and involuntary movements. Symptoms of nervous system problem depend on which area of the nervous system is involved and what is causing the problem. Nervous system problems may occur slowly and cause gradual loss of function. Or they may occur suddenly and cause life - threatening problems. Symptoms may be mild or severe. Some serious conditions, diseases, and injuries that can cause nervous system problems include: blood supply problems. Injuries, especially injuries to the head and spinal cord. Problems that are present at birth. Mental health problems, such as anxiety disorders, depression, or psychosis. Exposure to toxins, such as carbon monoxide, arsenic, or lead. Problems that cause gradual loss of function. Examples include: Parkinson's disease. Multiple sclerosis. Amyotrophic lateral sclerosis. Alzheimer's disease. Huntington's disease. Peripheral neuropathies. Infections. These may occur in the: Brain. The Membrane surrounds the brain and spinal cord. Overuse of or withdrawal from prescription and nonprescription medicines, illegal drugs, or alcohol. Brain tumor. Organ system failure. Examples include: Respiratory failure. Heart failure. Liver failure. Kidney failure. Other conditions. Some examples include: Thyroid dysfunction. High blood sugar or low blood sugar. Electrolyte problems. Nutritional deficiencies, such as vitamin B1 or vitamin B12 deficiency. Guillain - Barre syndrome. Sudden nervous system problems can cause many different symptoms, depending on the area of nervous system involve. Strokes and transient ischemic attacks are common examples of acute problems. You may experience sudden onset of one or more symptoms, such as: numbness, tingling, weakness, or inability to move part or all of one side of your body. Dimness, blurring, double vision, or loss of vision in one or both eyes. Loss of speech, trouble talking, or trouble understanding speech. Sudden, severe headache. Dizziness, unsteadiness, or inability to stand or walk, especially if other symptoms are present. Confusion or change in level of consciousness or behavior. Severe nausea or vomiting. Seizures can also cause sudden changes in consciousness, feeling,s emotion,s or thought.S Abnormal body movements, such as muscle twitching, may or may not be present. How often seizures occur and how severe they are depends on the cause of seizures and the area of the brain involve. For more information, see topic Seizures. Diabetes can cause problems with balance, either as a result of peripheral neuropathy or stroke. Vertigo and Dizziness are problems of balance and coordination.

* Please keep in mind that all text is machine-generated, we do not bear any responsibility, and you should always get advice from professionals before taking any actions.

* Please keep in mind that all text is machine-generated, we do not bear any responsibility, and you should always get advice from professionals before taking any actions

Study of the nervous system

Any man could, if he were so inclined, be sculptor of his own Brain. - Santiago Ramon y Cajal, Advice for Young Investigator Neuroscience is Scientific study of the nervous system and its functions. The belief that the brain is an organ that controls behavior has ancient roots, dating to early civilizations that connected loss of function to damage to parts of the brain and spinal cord. But the modern era of neuroscience began - and continues to progress - with the development of tools, techniques, and methods used to measure in ever more detail and complexity the structure and function of the nervous system. The modern era of neuroscience can be traced to the 1890s, when Spanish pathologist Santiago Ramon y Cajal used a method developed by Italian physician Camillo Golgi to stain nerve tissues to visualize the morphology and structure of neurons and their connections. A Detailed description of neurons and their connections by Cajal, his students, and their followers led to the neuron doctrine, which proposes that neurons are functional units of the nervous system. We now know that the human brain contains approximately one hundred billion neurons and that these neurons have some one hundred trillion connections, forming functional and definable circuits. These neural circuits can be organized into larger networks and anatomical structures that integrate information across and between all sensory modalities - including hearing, seeing, touching, tasting, and smelling - from all parts of the nervous system. These networks process information derived from internal and external environment, and the consequence of processing this sensory information is cognition, concept that includes learning and memory, perception, sleep, decision - making, emotions, and all forms of higher information processing. In response to simple or complex sensory experience, organism responds or behaves. Behavior can be simple, like motor reflex in response to pain, or more complicated, like playing squash, working crossword puzzle, or painting. However, behavior is not just what organisms do in response to stimulus or sensory input; it is most often what organisms choose to do from a variety of available options in response to a complex set of environmental conditions. Thus, except for rare responses, like simple reflexes, behavior is expressed in response to a combination of immediate sensory stimuli integrated over time with Cognition. Neuroscientists conduct experiments to understand how sensory information is processed to lead to behavior. Because of the obvious complexity of the brain, neuroscientists conduct their studies at different levels of depth. While neurons are conceivably the smallest units in which behavior can be clearly describe, neuron is itself made up of unique anatomical features, including soma, dendrites, and axons. These neuronal components in turn contain subcellular specializations that represent defining features of neuron. The key among these specializations is synapse: structure shared by dendrite and axon that represents junction point for the principal form of communication between two neurons.

* Please keep in mind that all text is machine-generated, we do not bear any responsibility, and you should always get advice from professionals before taking any actions.

* Please keep in mind that all text is machine-generated, we do not bear any responsibility, and you should always get advice from professionals before taking any actions

Stimulus-response coordination

Nervous system, organized group of cells specialize in conduction of electrochemical stimuli from sensory receptors through network to site at which response occur. All living organisms are able to detect changes within themselves and in their environments. Changes in the external environment include those of light, temperature, sound, motion, and odour, while changes in the internal environment include those in the position of head and limbs as well as in internal organs. Once detect, these internal and external changes must be analyzed and acted upon in order to survive. As life on Earth evolves and the environment becomes more complex, survival of organisms depends upon how well they can respond to changes in their surroundings. One factor necessary for survival was speedy reaction or response. Since communication from one cell to another by chemical means was too slow to be adequate for survival, systems evolved that allow for faster reaction. That system was nervous system, which is based upon almost instantaneous transmission of electrical impulses from one region of the body to another along specialized nerve cells called neurons. Nervous systems are of two general types, diffused and centralize. In diffuse type of system, found in lower invertebrates, there is no brain, and neurons are distributed throughout the organism in a netlike pattern. In centralized systems of higher invertebrates and vertebrates, portion of the nervous system has a dominant role in coordinating information and directing responses. This centralization reaches its culmination in vertebrates, which have a well - developed brain and spinal cord. Impulses are carried to and from the brain and spinal cord by nerve fibres that make up the peripheral nervous system. Invertebrate: Nervous system Nervous systems of flatworm and grasshopper. Encyclopdia Britannica, Inc. In primitive animals such as Hydra, marine organisms related to jellyfish and sea anemones, nervous systems consist of a diffuse net of individual nerve cells and fibres. Encyclopdia Britannica, Inc. In brain of mammals such as cat, olfactory bulb is still important, but greatly expanded cerebrum has assumed higher neural functions of correlation, association, and learning. Encyclopdia Britannica, Inc. This article begins with discussion of general features of the nervous systemsthat is, its function of responding to stimuli and rather uniform electrochemical processes by which they generate response. Following that is a discussion of various types of nervous systems, from the simplest to the most complex. The simplest type of response is a direct one - to - one stimulus - response reaction. Change in the environment is a stimulus; reaction of organism to it is a response. In single - celled organisms, response is the result of a property of cell fluid called irritability. In simple organisms, such as algae, protozoans, and fungi, response in which organism moves toward or away from stimulus is called taxis.

* Please keep in mind that all text is machine-generated, we do not bear any responsibility, and you should always get advice from professionals before taking any actions.

* Please keep in mind that all text is machine-generated, we do not bear any responsibility, and you should always get advice from professionals before taking any actions

Intracellular systems

Major Neurotransmitters and How They Affect Behavior

NeurotransmitterInvolved inPotential Effect on Behavior
AcetylcholineMuscle action, memoryIncreased arousal, enhanced cognition
Beta-endorphinPain, pleasureDecreased anxiety, decreased tension
DopamineMood, sleep, learningIncreased pleasure, suppressed appetite
Gamma-aminobutyric acid (GABA)Brain function, sleepDecreased anxiety, decreased tension
GlutamateMemory, learningIncreased learning, enhanced memory
NorepinephrineHeart, intestines, alertnessIncreased arousal, suppressed appetite
SerotoninMood, sleepModulated mood, suppressed appetite

Astrocytes are star - shaped gilal cells within the brain and spinal cord, Depending on method use they make up between 20 and 40% of all glial cells. They have numerous functions, including: providing metabolic support - the brain has a constant requirement for nutrients such as glucose but they are unable to store or produce glycogen themselves. This is overcome by the fact that astrocytes store glycogen which can be broken down to glucose to provide fuel for neurons. Astrocytes can also store lactate, which is useful as fuel during periods of high energy consumption or ischaemia. Regulating extracellular ionic environment - High - level of ions such as potassium can result in spontaneous depolarisation of neuron.S Astrocytes, thus, remove excess potassium ions from extracellular space. Neurotransmitter uptake - Astrocytes contain specific transporters for several neurotransmitters such as glutamate. Rapid removal of neurotransmitters from extracellular space is required for normal function of neurons. Modulating synaptic transmission - in some regions of the brain, for example the hippocampus, Astrocytes release ATP in order to increase production of adenosine, which in turn inhibits synaptic transmission. Promotion of myelination by oligodendrocytes Astrocytes are star - shaped gilal cells within the brain and spinal cord, Depending on method use they make up between 20 and 40% of all glial cells. They have numerous functions, including: providing metabolic support - the brain has a constant requirement for nutrients such as glucose but they are unable to store or produce glycogen themselves. This is overcome by the fact that astrocytes store glycogen which can be broken down to glucose to provide fuel for neurons. Astrocytes can also store lactate, which is useful as fuel during periods of high energy consumption or ischaemia. Regulating extracellular ionic environment - High - level of ions such as potassium can result in spontaneous depolarisation of neuron.S Astrocytes, thus, remove excess potassium ions from extracellular space. Neurotransmitter uptake - Astrocytes contain specific transporters for several neurotransmitters such as glutamate. Rapid removal of neurotransmitters from extracellular space is required for normal function of neurons. Modulating synaptic transmission - in some regions of the brain, for example the hippocampus, Astrocytes release ATP in order to increase production of adenosine, which in turn inhibits synaptic transmission. Promotion of myelination by oligodendrocytes These cells are responsible for insulating axons in the central nervous system. They carry out this function by producing a myelin sheath which wraps around part of the axon. A Single oligodendrocyte has the capacity to myelinate up to 50 axonal segments. They are equivalent to Schwann cells in the peripheral nervous system. Further information on myelin sheath can be found here. These cells are responsible for insulating axons in the central nervous system. They carry out this function by producing a myelin sheath which wraps around part of the axon. A Single oligodendrocyte has the capacity to myelinate up to 50 axonal segments. They are equivalent to Schwann cells in the peripheral nervous system. Further information on myelin sheath can be found here.

* Please keep in mind that all text is machine-generated, we do not bear any responsibility, and you should always get advice from professionals before taking any actions.

* Please keep in mind that all text is machine-generated, we do not bear any responsibility, and you should always get advice from professionals before taking any actions

What Does the Brain Do?

The brain is the control center of the body. It has wrinkled appearance due to bulges and depressions know as gyri and sulci. One of these furrows, medial longitudinal fissure, divides the brain into left and right hemispheres. Covering the brain is a protective layer of connective tissue know as meninges. Forebrain Midbrain Hindbrain forebrain is responsible for a variety of functions including receiving and processing sensory information, thinking, perceiving, producing and understanding language, and controlling motor function. The forebrain contains structures, such as the thalamus and hypothalamus, which are responsible for such functions as motor control, relaying sensory information, and controlling autonomic functions. It also contains the largest part of the brain, cerebrum. Most of actual information processing in the brain takes place in the cerebral cortex. The cerebral cortex is a thin layer of gray matter that covers the brain. It lies just beneath the meninges and is divided into four cortex lobes: These lobes are responsible for various functions in the body that include everything from sensory perception to decision - making and problem - solving. Below the cortex is the brain's white matter, which is composed of nerve cell axons that extend from neuron cell bodies of gray matter. White matter Nerve fiber tracts connect the cerebrum with different areas of the brain and spinal cord. The midbrain and hindbrain together make up the brainstem. The midbrain is the portion of the brainstem that connects the hindbrain and forebrain. This region of the brain is involved in auditory and visual responses as well as motor function. The hindbrain extends from the spinal cord and contains structures such as pons and cerebellum. These regions assist in maintaining balance and equilibrium, movement coordination, and conduction of sensory information. The hindbrain also contains medulla oblongata which is responsible for controlling such autonomic functions as breathing, heart rate, and digestion.


Brain and Nervous System

Considering everything it does, human brain is incredibly compact, weighing just 3 pounds. Its many folds and grooves, though, provide it with additional surface area necessary for storing all of bodys important information. Spinal cord, on the other hand, is a long bundle of nerve tissue about 18 inches long and inch thick. It extends from the lower part of the brain down through the spine. Along the way, various nerves branch out to the entire body. These make up the peripheral Nervous System. Both the brain and spinal cord are protected by bone: brain by bones of the skull, and the spinal cord by a set of ring - shape bones called vertebrae that make up the spine. They Theyre both cushioned by layers of membranes called meninges as well as special fluid called cerebrospinal fluid. This fluid helps protect nerve tissue, keep it healthy, and remove waste products. The brain is made up of three main sections: forebrain, midbrain, and hindbrain.


Spinal Cord

A common set of biological events take place following spinal cord injury: cells from the immune system migrate to the injury site, causing additional damage to some neurons and death to others that survive initial trauma. Death of oligodendrocytes causes axons to lose their myelination, which greatly impairs conduction of action potential, messages, or renders remaining connections useless. The Neuronal information highway is further disrupted because many axons are sever, cutting off lines of communication between the brain and muscles and between the body's sensory systems and the brain. Within several weeks of initial injury, area of tissue damage has been cleared away by microglia, and a fluid - filled cavity surrounded by glial scar is left behind. Molecules that inhibit regrowth of severed axons are now expressed at this site. Cavitation is called syrinx, which acts as a barrier to reconnection of two sides of the damaged spinal cord. Although spinal cord injury causes complex damage, surprising amount of basic circuitry to control movement and process information can remain intact. This is because the spinal cord is arranged in layers of circuitry. Many of the connections and neuronal cell bodies forming this circuitry above and below the site of injury survive trauma. An important question for research scientists is, how much do these surviving neurons know? Can they regenerate and make new, correct connections?


What is the central nervous system?

Neurons connect with one another to send and receive messages in the brain and spinal cord. Many neurons working together are responsible for every decision make, every emotion or sensation felt, and every action take. The complexity of the central nervous system is amazing: there are approximately 100 billion neurons in the brain and spinal cord combine. As many as 10 000 different subtypes of neurons have been identify, each specializing in sending and receiving certain types of information. Each neuron is made up of a cell body, which houses nucleus. Axons and dendrites form extensions from the cell body. Astrocytes, kind of glial cell, are primary support cells of the brain and spinal cord. They make and secrete proteins called neurotrophic factors. They also break down and remove proteins or chemicals that might be harmful to neurons. Astrocytes aren't always beneficial: after injury, they divide to make new cells that surround the injury site, forming a glial scar that is a barrier to regenerating axons. Microglia are immune cells for the brain. After injury, they migrate to the site of injury to help clear away dead and dying cells. They can also produce small molecules called cytokines that trigger cells of the immune system to respond to injury site. This clean - up process is likely to play an important role in recovery of function following spinal injury.

* Please keep in mind that all text is machine-generated, we do not bear any responsibility, and you should always get advice from professionals before taking any actions.

* Please keep in mind that all text is machine-generated, we do not bear any responsibility, and you should always get advice from professionals before taking any actions

Sources

* Please keep in mind that all text is machine-generated, we do not bear any responsibility, and you should always get advice from professionals before taking any actions.

* Please keep in mind that all text is machine-generated, we do not bear any responsibility, and you should always get advice from professionals before taking any actions

logo

Plex.page is an Online Knowledge, where all the summaries are written by a machine. We aim to collect all the knowledge the World Wide Web has to offer.

Partners:
Nvidia inception logo

© All rights reserved
2021 made by Algoritmi Vision Inc.

If you believe that any of the summaries on our website lead to misinformation, don't hesitate to contact us. We will immediately review it and remove the summaries if necessary.

If your domain is listed as one of the sources on any summary, you can consider participating in the "Online Knowledge" program, if you want to proceed, please follow these instructions to apply.
However, if you still want us to remove all links leading to your domain from Plex.page and never use your website as a source, please follow these instructions.