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Encyclopedia > Nervous system
Neuroscience Portal

The nervous system is a highly specialized network whose principal components are nerves called neurons. Neurons are interconnected to each other in complex arrangements, and have the property of conducting, using electrochemical signals, a great variety of stimuli both within the nervous tissue as well as from and towards most of the other tissues. Thus, neurons coordinate multiple functions in organisms. Nervous systems are found in many multicellular animals but differ greatly in complexity between species. Image File history File links Question_book-3. ... Image File history File links No higher resolution available. ... This article is about cells in the nervous system. ... For other uses, see Animal (disambiguation). ...

The Human Nervous System. Red is CNS and blue is PNS.
The Human Nervous System. Red is CNS and blue is PNS.

Contents

Image File history File links Size of this preview: 363 × 599 pixelsFull resolution (421 × 695 pixel, file size: 176 KB, MIME type: image/png) A diagram of the Human Nervous system for the nervous system article. ... Image File history File links Size of this preview: 363 × 599 pixelsFull resolution (421 × 695 pixel, file size: 176 KB, MIME type: image/png) A diagram of the Human Nervous system for the nervous system article. ...

Nervous system in humans

The human nervous system can be observed both with gross anatomy, (which describes the parts that are large enough to be seen with the plain eye,) and microanatomy, (which describes the system at a cellular level.) At gross anatomy, the nervous system can be grouped in distinct organs, these being actually stations which the neural pathways cross through. Thus, with a didactical purpose, these organs, according to their ubication, can be divided in two parts: the central nervous system (CNS) and the peripheral nervous system (PNS). The 1989 movie Gross Anatomy stars Matthew Modine and Daphne Zuniga. ... A thin section of lung tissue stained with hematoxylin and eosin. ...


Central nervous system

See also: List of regions in the human brain

The central nervous system (CNS) represents the largest part of the nervous system, including the brain and the spinal cord. The CNS is contained within the dorsal cavity, with the brain within the cranial cavity, and the spinal cord in the spinal cavity. The CNS is covered by the meninges. The brain is also protected by the skull, and the spinal cord is also protected by the vertebrae. The nervous system can be connected into many systems that can function together. The two systems are central nervous system (CNS)and the peripheral nervous system (PNS). A diagram showing the CNS: 1. ... // medulla oblongata medullary pyramids pons paramedian pontine reticular formation fourth ventricle cerebellum cerebellar vermis cerebellar hemispheres anterior lobe posterior lobe flocculonodular lobe cerebellar nuclei fastigial nucleus globose nucleus emboliform nucleus dentate nucleus tectum inferior colliculi superior colliculi mesencephalic duct (cerebral aqueduct, Aqueduct of Sylvius) cerebral peduncle midbrain tegmentum ventral tegmental... Human brain In animals, the brain (enkephale) (Greek for in the skull), is the control center of the central nervous system, responsible for behavior. ... The Spinal cord nested in the vertebral column. ... The human body consists of the following body cavities: dorsal body cavity cranial cavity, enclosed by the Skull and contains the brain, eyes, and ears. ...   The cranial cavity isj the relatively large space formed inside the skull. ... The spinal canal is the space in vertebrae through which the spinal cord passes. ... The meninges (singular meninx) are the system of membranes that envelop the central nervous system. ...

Central
nervous
system
Brain Prosencephalon Telencephalon

Rhinencephalon, Amygdala, Hippocampus, Neocortex, Lateral ventricles A diagram showing the CNS: 1. ... Human brain In animals, the brain (enkephale) (Greek for in the skull), is the control center of the central nervous system, responsible for behavior. ... In the anatomy of vertebrates, the prosencephalon is a part of encephalon, or brain. ... The telencephalon (te-len-seff-a-lon) is the technical name for a large region within the brain which is attributed many functions, which some groups would class as unique features which make humans stand out from other species. ... In animal anatomy, the rhinencephalon is a part of the brain involved with olfaction. ... Look up Amygdala in Wiktionary, the free dictionary. ... For other uses, see Hippocampus (disambiguation). ... The neocortex (Latin for new bark or new rind) is a part of the brain of mammals. ... The ventricular system is a fluid conducting system within the brain. ...

Diencephalon

Epithalamus, Thalamus, Hypothalamus, Subthalamus, Pituitary gland, Pineal gland, Third ventricle The diencephalon is the region of the brain that includes the epithalamus, thalamus, and hypothalamus. ... The epithalamus is a dorsal posterior segment of the diencephalon (a segment in the middle of the brain also containing the hypothalamus and the thalamus) which includes the habenula, the stria medullaris and the pineal body. ... The thalamus (from Greek θάλαμος = bedroom, chamber, IPA= /ˈθæləməs/) is a pair and symmetric part of the brain. ... The hypothalamus links the nervous system to the endocrine system via the pituitary gland (hypophysis). ... The subthalamus, or ventral thalamus, is part of the diencephalon. ... | Latin = hypophysis, glandula pituitaria | GraySubject = 275 | GrayPage = 1275 | Image = Gray1180. ... The pineal gland (also called the pineal body or epiphysis) is a small endocrine gland in the brain. ... The third ventricle is one of the four connected fluid-filled cavities within the human brain. ...

Brain stem Mesencephalon

Tectum, Cerebral peduncle, Pretectum, Mesencephalic duct The brain stem is the lower part of the brain, adjoining and structurally continuous with the spinal cord. ... In biological anatomy, the mesencephalon (or midbrain) is the middle of three vesicles that arise from the neural tube that forms the brain of developing animals. ... The tectum is the dorsal part of the midbrain, derived in embryonic development from the alar plate of the neural tube. ... The cerebral peduncle, by most classifications, is everything in the mesencephalon except the tectum. ... Pretectum is a structure located in the forebrain. ... The mesencephalic duct, also known as the aqueduct of Silvius or the cerebral aqueduct, contains cerebrospinal fluid (CSF), is within the mesencephalon (or midbrain) and connects the third ventricle in the thalamus (or diencephalon) to the fourth ventricle, which is between the pons and cerebellum. ...

Rhombencephalon Metencephalon

Pons, Cerebellum, The rhombencephalon (or hindbrain) is a developmental categorization of portions of the central nervous system in vertebrates. ... The metencephalon is a developmental categorization of portions of the central nervous system. ... For other uses, see Pons (disambiguation). ... The cerebellum (Latin: little brain) is a region of the brain that plays an important role in the integration of sensory perception and motor control. ...

Myelencephalon Medulla oblongata
Spinal cord

The myelencephalon is a developmental categorization of a portion of the central nervous system. ... The medulla oblongata is the lower portion of the brainstem. ... The Spinal cord nested in the vertebral column. ...

Peripheral nervous system

The PNS consists of all the other nervous structures that do not lie within it. The large majority of what are commonly called nerves (which are actually axonal processes of nerve cells) are considered to be PNS. The Peripheral nervous system resides or extends outside the CNS central nervous system (the brain and spinal cord) to serve the limbs and organs. ...


Microanatomy

The nervous system is, on a small scale, primarily made up of neurons. However, glial cells also play a major role. Neurons (also called nerve cells) are the primary cells of the nervous system. ... Neuroglia of the brain shown by Golgis method. ...


Neurons

Main article: Neuron

They are the core components of both the central nervous system & peripheral nervous system. Neurons are sensors that send electric messages to the Central Nervous System which send the electric messages back to the neurons telling them how to react, where the messages are finally sent back directly to the brain. These messages travel at a usual pace of 100 meters per second. This article is about cells in the nervous system. ... A diagram showing the CNS: 1. ... The Peripheral nervous system resides or extends outside the CNS central nervous system (the brain and spinal cord) to serve the limbs and organs. ...


Glial cells

Main article: Glial cell

Glial cells are non-neuronal cells that provide support and nutrition, maintain homeostasis, form myelin, and participate in signal transmission in the nervous system. In the human brain, glia are estimated to outnumber neurons by about 10 to 1.[1] Neuroglia of the brain shown by Golgis method. ... This article is about cells in the nervous system. ... Drawing of the structure of cork as it appeared under the microscope to Robert Hooke from Micrographia which is the origin of the word cell being used to describe the smallest unit of a living organism Cells in culture, stained for keratin (red) and DNA (green) The cell is the... Homeostasis is the property of either an open system or a closed system, especially a living organism, which regulates its internal environment so as to maintain a stable, constant condition. ... Myelin is an electrically insulating phospholipid layer that surrounds the axons of many neurons. ... The human brain controls the central nervous system (CNS), by way of the cranial nerves and spinal cord, the peripheral nervous system (PNS) and regulates virtually all human activity. ...


Glial cells provide support and protection for neurons. They are thus known as the "glue" of the nervous system. The four main functions of glial cells are to surround neurons and hold them in place, to supply nutrients and oxygen to neurons, to insulate one neuron from another, and to destroy pathogens and remove dead neurons. This article is about cells in the nervous system. ... Nutrients and the body A nutrient is any element or compound necessary for or contributing to an organisms metabolism, growth, or other functioning. ... This article is about the chemical element and its most stable form, or dioxygen. ... A pathogen (literally birth of pain from the Greek παθογένεια) is a biological agent that can cause disease to its host. ...


Physiological division

A less anatomical but much more functional division of the human nervous system is that classifying it according to the role that the different neural pathways play, regardless whether these cross through the CNS or the PNS:


The somatic nervous system is responsible for coordinating the body's movements, and also for receiving external stimuli. It is the system that regulates activities that are under conscious control. The somatic nervous system is that part of the peripheral nervous system associated with the voluntary control of body movements through the action of skeletal muscles, and also reception of external stimuli. ...


The autonomic nervous system is then split into 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 one's heartbeat and blood pressure, among other physiological changes, along with the sense of excitement one feels due to the increase of adrenaline in the system. The parasympathetic nervous system, on the other hand, is evident when a person is resting and feels relaxed, and is responsible for such things as 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 role of the enteric nervous system is to manage every aspect of digestion, from the esophagus to the stomach, small intestine and colon. This article or section is in need of attention from an expert on the subject. ... The Sympathetic Nervous System (SNS) is a branch of the autonomic nervous system. ... Autonomic nervous system innervation, showing the sympathetic and parasympathetic (craniosacral) systems, in red and blue, respectively The parasympathetic nervous system is one of three divisions of the autonomic nervous system. ... The enteric nervous system (ENS) is an interdependent part of the autonomic nervous system. ... Epinephrine (INN) or adrenaline (BAN) is a hormone and a neurotransmitter. ... This page is a candidate to be moved to Wiktionary. ...


In turn, these pathways can be divided according to the direction in which they conduct stimuli:

  • Afferent system by sensory neurons, which carry impulses from a receptor to the CNS
  • Efferent system by motor neurons, which carry impulses from the CNS to an effector
  • Relay system by relay neurons (also called interneurons), which transmit impulses between the sensory and motor neurones.

A useful mnemonic to remember the nature of Afferent vs Efferent is SAME DAVE: Sensory Afferent, Motor Efferent; Dorsal Afferent, Ventral Efferent The mechanism of the reflex arc Sensory neurons (neurones) are nerve cells within the nervous system responsible for converting external stimuli from the organisms environment into internal electrical motor reflex loops and several forms of involuntary behavior, including pain avoidance. ... In vertebrates, the term motor neuron (or motoneuron) classically applies to neurons located in the central nervous system (CNS) which project their axons outside the CNS and directly or indirectly control muscles. ... An interneuron (also called relay neuron,association neuron or bipolar neuron) is a term used to describe a neuron which has two different common meanings. ...


However, there are relay neurons in the CNS as well.


The junction between two neurones is called a synapse. There is a very narrow gap (about 20nm in width) between the neurons - the synaptic cleft, where an action potential is transmitted from one neuron to a neighboring one. They do this by relaying the message with the use of neurotransmitters which the next neuron then receives the electrical signal, known as a nerve impulse. The nerve impulse is determined by the neurotransmitter to then carry the message to its appropriate destination. These nerve impulses are a change in ion balance in the nerve cell, which the central nervous system can then interpret. The fact that the nervous system uses a mixture of electrical and chemical signals makes it incredibly fast, which is necessary to acknowledge the presence of danger. For example, a hand touching a hot stove. If the nervous system was only comprised of chemical signals, the body would not tell the arm to move fast enough to escape dangerous burns. So the speed of the nervous system is a necessity for life. Illustration of the major elements in a prototypical synapse. ... Synapses allow nerve cells to communicate with one another through axons and dendrites, converting electrical signals into chemical ones. ... Neurotransmitters are chemicals that are used to relay, amplify and modulate electrical signals between a presynaptic and a postsynaptic neuron. ... Schematic of an electrophysiological recording of an action potential showing the various phases which occur as the wave passes a point on a cell membrane. ...

Physiological division Somatic nervous system Afferent system
Efferent system
Autonomic nervous system Sympathetic Afferent system
Efferent system
Parasympathetic Afferent system
Efferent system

The somatic nervous system is that part of the peripheral nervous system associated with the voluntary control of body movements through the action of skeletal muscles, and also reception of external stimuli. ... The mechanism of the reflex arc In the nervous system, afferent neurons--otherwise known as sensory or receptor neurons--carry nerve impulses from receptors or sense organs toward the central nervous system. ... The mechanism of the reflex arc In the nervous system, efferent nerves – otherwise known as motor or effector neurons – carry nerve impulses away from the central nervous system to effectors such as muscles or glands (and also the ciliated cells of the inner ear). ... This article or section is in need of attention from an expert on the subject. ... The Sympathetic Nervous System (SNS) is a branch of the autonomic nervous system. ... The mechanism of the reflex arc In the nervous system, afferent neurons--otherwise known as sensory or receptor neurons--carry nerve impulses from receptors or sense organs toward the central nervous system. ... The mechanism of the reflex arc In the nervous system, efferent nerves – otherwise known as motor or effector neurons – carry nerve impulses away from the central nervous system to effectors such as muscles or glands (and also the ciliated cells of the inner ear). ... Autonomic nervous system innervation, showing the sympathetic and parasympathetic (craniosacral) systems, in red and blue, respectively The parasympathetic nervous system is one of three divisions of the autonomic nervous system. ... The mechanism of the reflex arc In the nervous system, afferent neurons--otherwise known as sensory or receptor neurons--carry nerve impulses from receptors or sense organs toward the central nervous system. ... The mechanism of the reflex arc In the nervous system, efferent nerves – otherwise known as motor or effector neurons – carry nerve impulses away from the central nervous system to effectors such as muscles or glands (and also the ciliated cells of the inner ear). ...

Development

Main article: Neural development in humans

Some landmarks of embryonic neural development include the birth and differentiation of neurons from stem cell precursors, the migration of immature neurons from their birthplaces in the embryo to their final positions, outgrowth of axons from neurons and guidance of the motile growth cone through the embryo towards postsynaptic partners, the generation of synapses between these axons and their postsynaptic partners, and finally the lifelong changes in synapses which are thought to underlie learning and memory. The study of neural development draws on both neuroscience and developmental biology to describe the cellular and molecular mechanisms by which complex nervous systems emerge during embryonic development and throughout life. ... For other uses, see Embryo (disambiguation). ... Embryonic stem cells differentiate into cells in various body organs. ... This article is about cells in the nervous system. ... Mouse embryonic stem cells. ... Cellular migration is the movement of cells in the body to their proper position. ... An axon or nerve fiber, is a long, slender projection of a nerve cell, or neuron, that conducts electrical impulses away from the neurons cell body or soma. ... This article or section does not cite any references or sources. ... Image of a growth cone (red) extending from an axon (green). ... Illustration of the major elements in a prototypical synapse. ... In neuroscience, synaptic plasticity is the ability of the connection, or synapse, between two neurons to change in strength. ...


Importance

Many people have lost basic motor skills and other skills because of spinal chord injuries. If this portion is damaged, the biggest nerve and the most important one gets damaged. This leads to paralysis or other permanent damages.


Non-humans

Vertebrates

The nervous system of all vertebrate animals, is often divided into the central nervous system (CNS) and the peripheral nervous system (PNS). The CNS consists of the brain and spinal cord.


Worms

Planaria, a type of flatworm, have dual nerve cords running along the length of the body and merging at the tail and the mouth. These nerve cords are connected by transverse nerves like the rungs of a ladder. These transverse nerves help coordinate the two sides of the animal. Two large ganglia at the head end function similar to a simple brain. Photoreceptors on the animal's eyespots provide sensory information on light and dark. Planaria sp. ... Classes Monogenea Trematoda Cestoda Turbellaria Wikimedia Commons has media related to: Platyhelminthes Wikispecies has information related to: Platyhelminthes The flatworms (Phylum Platyhelminthes from the Greek platy, meaning flat and helminth, meaning worm) are a phylum of relatively simple soft-bodied invertebrate animals. ... The ventral nerve cords make up the nervous system of arthropods. ... The term transverse means side-to-side, as opposed to longitudinal, which means front-to-back. In automotive engineering, the term transverse refers to an engine in which the crankshaft is oriented side-to-side relative to the wheels of the vehicle. ... See Cartesian coordinate system or Coordinates (elementary mathematics) for a more elementary introduction to this topic. ... GÃ…NGLÃŽÃ… is a 1 man electronic grindcore band from Los Angeles California that began in August of 1999. ... A photoreceptor, or photoreceptor cell, is a specialized type of neuron found in the eyes retina that is capable of phototransduction. ...


The nervous system of the roundworm Caenorhabditis elegans has been mapped out to the cellular level. Every neuron and its cellular lineage has been recorded and most, if not all, of the neural connections are known. In this species, the nervous system is sexually dimorphic; the nervous systems of the two sexes, males and hermaphrodites, have different numbers of neurons and groups of neurons that perform sex-specific functions. In C. elegans, males have exactly 383 neurons, while hermaphrodites have exactly 302 neurons [1] Classes Adenophorea    Subclass Enoplia    Subclass Chromadoria Secernentea    Subclass Rhabditia    Subclass Spiruria    Subclass Diplogasteria The roundworms or nematodes (Phylum Nematoda from Gr. ... Binomial name Maupas, 1900 Caenorhabditis elegans (IPA: ) is a free-living nematode (roundworm), about 1 mm in length, which lives in temperate soil environments. ... Female (left) and male Common Pheasant, illustrating the dramatic difference in form between the sexes Sexual dimorphism is the systematic difference in form between individuals of different sex in the same species. ... In zoology, a hermaphrodite is a species that contains both male and female sexual organs at some point during their lives. ...


Arthropoda

Arthropods, such as insects and crustaceans, have a nervous system made up of a series of ganglia, connected by a ventral nerve cord made up of two parallel connectives running along the length of the belly [2]. Typically, each body segment has one ganglion on each side, though some ganglia are fused to form the brain and other large ganglia [3]. Subphyla and Classes Subphylum Trilobitomorpha Trilobita - trilobites (extinct) Subphylum Chelicerata Arachnida - spiders,scorpions, etc. ... Orders Subclass Apterygota Archaeognatha (bristletails) Thysanura (silverfish) Subclass Pterygota Infraclass Paleoptera (Probably paraphyletic) Ephemeroptera (mayflies) Odonata (dragonflies and damselflies) Infraclass Neoptera Superorder Exopterygota Grylloblattodea (ice-crawlers) Mantophasmatodea (gladiators) Plecoptera (stoneflies) Embioptera (webspinners) Zoraptera (angel insects) Dermaptera (earwigs) Orthoptera (grasshoppers, etc) Phasmatodea (stick insects) Blattodea (cockroaches) Isoptera (termites) Mantodea (mantids) Psocoptera... For the Dutch band, see Crustacean (band). ... This is a dorsal root ganglion (DRG) from a chicken embryo (around stage of day 7) after incubation overnight in NGF growth medium stained with anti-neurofilament antibody. ... The ventral nerve cords make up the nervous system of arthropods. ... Look up belly in Wiktionary, the free dictionary. ... This is a dorsal root ganglion (DRG) from a chicken embryo (around stage of day 7) after incubation overnight in NGF growth medium stained with anti-neurofilament antibody. ...


The head segment contains the brain, also known as the supraesophageal ganglion. In the insect nervous system, the brain is anatomically divided into the protocerebrum, deutocerebrum, and tritocerebrum. Immediately behind the brain is the subesophageal ganglion, which is composed of three pairs of fused ganglia. It controls the mouthparts, the salivary glands and certain muscles. Human brain In animals, the brain (enkephale) (Greek for in the skull), is the control center of the central nervous system, responsible for behavior. ... Orders Subclass Apterygota Archaeognatha (bristletails) Thysanura (silverfish) Subclass Pterygota Infraclass Paleoptera (Probably paraphyletic) Ephemeroptera (mayflies) Odonata (dragonflies and damselflies) Infraclass Neoptera Superorder Exopterygota Grylloblattodea (ice-crawlers) Mantophasmatodea (gladiators) Plecoptera (stoneflies) Embioptera (webspinners) Zoraptera (angel insects) Dermaptera (earwigs) Orthoptera (grasshoppers, etc) Phasmatodea (stick insects) Blattodea (cockroaches) Isoptera (termites) Mantodea (mantids) Psocoptera... The subesophageal ganglion of insects is composed of three pairs of fused ganglia. ... The mouthparts of arthropods have evolved into a number of forms, each adapted to a different style of feeding. ... The salivary glands produce saliva, which keeps the mouth and other parts of the digestive system moist. ... For other uses of Muscles, see Muscles (disambiguation). ...


Many arthropods have well-developed sensory organs, including compound eyes for vision and antennae for olfaction and pheromone sensation. The sensory information from these organs is processed by the brain. This article is about the senses of living organisms (vision, taste, etc. ... Compound eye of a dragonfly A compound eye is a visual organ found in arthropods such as insects and crustaceans. ... Insects display a wide variety of antennal shapes. ... Olfaction (also known as olfactics) refers to the sense of smell. ... Fanning honeybee exposes Nasonov gland (white-at tip of abdomen) releasing pheromone to entice swarm into an empty hive A pheromone (from Greek φέρω phero to bear + ‘ορμόνη hormone) is a chemical that triggers a natural behavioral response in another member of the same species. ...


Development

Main article: Neural development

Neural development in most species have many similarities neural development in humans. The study of neural development draws on both neuroscience and developmental biology to describe the cellular and molecular mechanisms by which complex nervous systems emerge during embryonic development and throughout life. ... The study of neural development draws on both neuroscience and developmental biology to describe the cellular and molecular mechanisms by which complex nervous systems emerge during embryonic development and throughout life. ...


External links

The alar plate (or alar lamina) is a neural structure in the embryonic nervous system, part of the dorsal side of neural tube, that involves the communication of general somatic and general visceral sensory impulses. ... This article is about the structure in the developing nervous system. ... Transverse section showing the lens and the optic cup. ... The eyes begin to develop as a pair of diverticula from the lateral aspects of the forebrain. ... The optic vesicles project toward the sides of the head, and the peripheral part of each expands to form a hollow bulb, while the proximal part remains narrow and constitutes the optic stalk. ... During embryonic development of the eye, the outer wall of the bulb of the optic vesicles becomes thickened and invaginated, and the bulb is thus converted into a cup, the optic cup (or ophthalmic cup), consisting of two strata of cells). ... The Lens placode is a thickened portion of ectoderm which serves as the precursor to the lens. ... The mouth of the auditory pit is then closed, and thus a shut sac, the auditory vesicle (or otic vesicle[1]), is formed; from it the epithelial lining of the membranous labyrinth is derived. ... The first rudiment of the internal ear appears shortly after that of the eye, in the form of a patch of thickened ectoderm, the auditory plate, over the region of the hind-brain. ... A thin section of lung tissue stained with hematoxylin and eosin. ... Nervous tissue is the fourth major class of vertebrate tissue. ... This article is about cells in the nervous system. ... Grey matter (or gray matter) is a major component of the central nervous system, consisting of nerve cell bodies, glial cells (astroglia and oligodendrocytes), capillaries, and short nerve cell extensions/processes (axons and dendrites). ... The soma, or perikaryon, is the bulbous end of a neuron, containing the cell nucleus. ... An axon or nerve fiber, is a long, slender projection of a nerve cell, or neuron, that conducts electrical impulses away from the neurons cell body or soma. ... The arrow labeled axon is pointing directly at the axon hillock. ... Axoplasm is the cytoplasm of the axon of a neuron. ... The axolemma is the membrane of a neurons axon. ... Intermediate filaments are one component of the cytoskeleton - important structural components of living cells. ... Dendrites (from Greek dendron, “tree”) are the branched projections of a neuron that act to conduct the electrical stimulation received from other neural cells to the cell body, or soma, of the neuron from which the dendrites project. ... Image of a Nissl-stained histological section through the rodent hippocampus showing various classes of neurons. ... Close up of the dendrite of a striatal medium spiny neuron. ... An apical dendrite is a dendrite that emerges from the apex of a pyramidal cell. ... A basal dendrite is a dendrite that emerges from the base of a pyramidal cell. ... As a part of the retina, the bipolar cell exists between photoreceptors (rod cells and cone cells) and ganglion cells. ... Pseudounipolar cells (Pseudo- false, uni- one) are sensory neurons in the peripheral nervous system. ... The multipolar neuron possesses a single (usually long) axon and many dendrites, allowing for the integration of a great deal of information from other neurons. ... A pyramidal cell (or pyramidal neuron, or projection neuron) is a multipolar neuron located in the hippocampus and cerebral cortex. ... Drawing of pigeon Purkinje cells (A) by Santiago Ramon y Cajal Purkinje cells are a class of GABAergic neuron located in the cerebellar cortex. ... In neuroscience, granule cells are tiny cells found within the granular layer of the cerebellum. ... The mechanism of the reflex arc In the nervous system, afferent neurons--otherwise known as sensory or receptor neurons--carry nerve impulses from receptors or sense organs toward the central nervous system. ... The mechanism of the reflex arc Sensory neurons (or neurones) are nerve cells within the nervous system responsible for converting external stimuli from the organisms environment into internal electrical impulses. ... The mechanism of the reflex arc Sensory neurons (neurones) are nerve cells within the nervous system responsible for converting external stimuli from the organisms environment into internal electrical motor reflex loops and several forms of involuntary behavior, including pain avoidance. ... The general somatic afferent fibers (or somatic sensory fibers), afferent fibers, arise from cells in the spinal ganglia and are found in all the spinal nerves, except occasionally the first cervical, and conduct impulses of pain, touch and temperature from the surface of the body through the posterior roots to... The general visceral afferent fibers (GVA, or sympathetic afferent fibers), conduct sensory impulses from the viscera through the rami communicantes and posterior roots to the spinal cord. ... Special somatic afferent (SSA) refers to efferent nerves which supply muscles derived from ectoderm. ... Special visceral afferent (SVA) refers to afferent nerves supporting the gastrointestinal tract. ... An axon or nerve fiber, is a long, slender projection of a nerve cell, or neuron, that conducts electrical impulses away from the neurons cell body or soma. ... Type Ia Sensory Fiber also called Primary Afferent Type 1A Fiber or Group II sensory fibers is a component of a muscle fibers muscle spindle which keeps track of the how fast a muscle stretch changes (the velocity of the stretch). ... Organ of Golgi (neurotendinous spindle) from the human tendo calcaneus. ... Type II sensory fiber are the second of the two main groups of stretch receptors. ... A delta fibers (Aδ) are the fibers which convey fast pain information. ... C-fibers are unmyeliniated and as a result, have a slower conduction velocity, lower than 2 m/s. ... In the nervous system, efferent nerves otherwise known as motor or effector neuron carry nerve impulses away from the central nervous systemto effectors - either muscles or glands. ... Motor nerves allow the brain to stimulate muscle contraction. ... In vertebrates, the term motor neuron (or motoneuron) classically applies to neurons located in the central nervous system (CNS) which project their axons outside the CNS and directly or indirectly control muscles. ... The general somatic efferent fibers (or somatic motor fibers), efferent fibers, arise from cells in the anterior column of the spinal cord and pass out through the anterior roots to the voluntary muscles. ... The general visceral efferent fibers (GVE or sympathetic efferent fibers), probably arise from cells in the lateral column or the base of the anterior column and emerge through the anterior roots and white rami communicantes. ... Special visceral efferent (SVE) refers to efferent nerves which supply muscles which derived from the branchial arches. ... Upper motor neurons are any neurons that carry motor information down to the final common pathway, that is, any neurons that are not directly responsible for stimulating the target muscle. ... Lower motor neurons (LMNs) are the motoneurons connecting the brainstem and spinal cord to muscle fibers, bringing the nerve impulses from the upper motor neurons out to the muscles. ... Alpha motor neurons (α-MNs) are large lower motor neurons of the brainstem and spinal cord. ... A muscle spindle, with γ motor and Ia sensory fibers Gamma motoneurons (γ-motoneurons), also called gamma motor neurons, are a component of the fusimotor system, the system by which the central nervous system controls muscle spindle sensitivity. ... Illustration of the major elements in a prototypical synapse. ... Neuropil is the feltwork of unmyelinated neuronal processes (axonal and dendritic) within the gray matter of the central nervous system Traditionally, when pathologists looked at brain tissue they concentrated on neurons (the active functioning cells of the brain), glial cells and axons (especially in white matter, which is mostly composed... In a neuron, synaptic vesicles, also called neurotransmitter vesicles, store the various neurotransmitters that are released during calcium-regulated exocytosis at the presynaptic terminal into the synaptic cleft of a synapse. ... A neuromuscular junction is the junction of the axon terminal of a motoneuron with the motor end plate, the highly-excitable region of muscle fiber plasma membrane responsible for initiation of action potentials across the muscles surface. ... An electrical synapse is a mechanical and electrically conductive link between two abutting neurons that is formed at a narrow gap between the pre- and postsynaptic cells known as a gap junction. ... An interneuron (also called relay neuron,association neuron or bipolar neuron) is a term used to describe a neuron which has two different common meanings. ... Renshaw cells are located in the spinal cord horn. ... In a sensory system, a sensory receptor is a structure that recognizes a stimulus in the internal or external environment of an organism. ... NERVE ENDINGS SUCK PENIS!!! ... Meissners corpuscles (discovered by the anatomist Georg Meissner (1829-1903) are a type of mechanoreceptor and more specifically, a tactile corpuscle(corpusculum tactus). ... Merkel nerve endings are mechanoreceptors found in the skin and mucosa of vertebrates that provide touch information to the brain. ... A muscle spindle is a specialized muscle structure innervated by both sensory and motor neuron axons. ... A Pacinian corpuscle is a structure that functions as a mechanoreceptor. ... Ruffini Endings are one of the four main cutaneous mechanoreceptors. ... Bold text == Headline text == minni hi. ... This article is about cellular photoreceptors. ... Hair cells are the sensory cells of both the auditory system and the vestibular system in all vertebrates. ... Taste buds are small structures on the upper surface of the tongue, soft palate, and epiglottis that provide information about the taste of food being eaten. ... Neuroglia of the brain shown by Golgis method. ... Astrocytes (also known collectively as astroglia) are characteristic star-shaped glial cells in the brain. ... Oligodendrocytes (from Greek literally meaning few tree cells), or oligodendroglia (Greek, few tree glue),[1] are a variety of neuroglia. ... Ependyma is the thin epithelial membrane lining the ventricular system of the brain and the spinal cord canal. ... Microglia cells positive for lectins Microglia are a type of glial cell that act as the immune cells of the Central nervous system (CNS). ... Radial glial cells are a pivotal cell type in the developing CNS involved in key developmental processes, ranging from patterning and neuronal migration to their newly described role as precursors during neurogenesis. ... Myelin is an electrically insulating phospholipid layer that surrounds the axons of many neurons. ... White matter is one of the two main solid components of the central nervous system. ... Named after the German physiologist Theodor Schwann, Schwann cells are a variety of neuroglia that mainly provide myelin insulation to axons in the peripheral nervous system of jawed vertebrates. ... Oligodendrocytes (from Greek literally meaning few tree cells), or oligodendroglia (Greek, few tree glue),[1] are a variety of neuroglia. ... This article is about anatomy; for the musical group see Nodes of Ranvier (band) Nodes of Ranvier are regularly spaced gaps in the myelin sheath around an axon or nerve fiber. ... The portion of nerve fiber between two Nodes of Ranvier is called an internodal segment (or internode). ... Oblique clefts may be seen in the medullary sheath, subdividing it into irregular portions, which are termed Schmidt-Lanterman incisures (or clefts of schmidt-lanterman, segments of Lantermann, medullary segments. ... Neurolemma (spelled also neurolema, neurilemma and neurilema, and used interchangeably with epineurium) is the insulating myelin layer that surrounds an individual peripheral nerve fiber. ... Connective tissue is one of the four types of tissue in traditional classifications (the others being epithelial, muscle, and nervous tissue. ... Neurolemma (spelled also neurolema, neurilemma and neurilema, and used interchangeably with epineurium) is the insulating myelin layer that surrounds an individual peripheral nerve fiber. ... In a nerve fiber, the tubular sheath of the funiculi, perineurium, is a fine, smooth, transparent membrane, which may be easily separated, in the form of a tube, from the fibers it encloses; in structure it is made up of connective tissue, which has a distinctly lamellar arrangement. ... The nerve fibers are held together and supported within the funiculus by delicate connective tissue, called the endoneurium. ... A small bundle of fibers, enclosed in a tubular sheath, is called a funiculus; if the nerve is of small size, it may consist only of a single funiculus; but if large, the funiculi are collected together into larger bundles or nerve fascicles, which are bound together in a common... The meninges (singular meninx) are the system of membranes that envelop the central nervous system. ... A renal cell carcinoma (chromophobe type) viewed on a hematoxylin & eosin stained slide Pathologist redirects here. ... Inflammation is the first response of the immune system to infection or irritation and may be referred to as the innate cascade. ... A diagram showing the CNS: 1. ... Meningitis is the inflammation of the protective membranes covering the central nervous system, known collectively as the meninges. ... Arachnoiditis describes a pain disorder caused by the inflammation of the arachnoid, one of the membranes that surround and protect the nerves of the spinal cord. ... Encephalitis is an acute inflammation of the brain, commonly caused by a viral infection. ... Myelitis is a human disease involving swelling of the spinal cord, which disrupts central nervous system functions linking brain and limbs. ... Encephalomyelitis is a general term for inflammation of the brain and spinal cord, describing a number of disorders: acute disseminated encephalomyelitis or postinfectious encephalomyelitis, a demyelinating disease of the brain and spinal cord, possibly triggered by vaccination or viral infection; encephalomyelitis disseminata, a synonym for multiple sclerosis; equine encephalomyelitis, a... Acute disseminated encephalomyelitis (ADEM) is an immune mediated disease of brain. ... Tropical spastic paraparesis (TSP) is an infection of the spinal cord by Human T-lymphotropic virus resulting in paraparesis or weakness of the legs. ... Atrophy is the partial or complete wasting away of a part of the body. ... Spinocerebellar ataxia (SCA) is a genetic disease with multiple types, each of which could be considered a disease in its own right. ... Friedreichs ataxia is a rare autosomal recessive disorder caused by a mutation in Gene X25 that codes for frataxin, located on chromosome 9. ... Ataxia-telangiectasia (AT) (Boder-Sedgwick syndrome or Louis-Bar syndrome) is a primary immunodeficiency disorder that occurs in an estimated incidence of 1 in 40,000 to 1 in 300,000 births (Lederman, 2000). ... Hereditary spastic paraplegia (HSP), also called familial spastic paraparesis (FSP), refers to a group of inherited disorders that are characterized by progressive weakness and stiffness of the legs. ... Spinal Muscular Atrophy (SMA) is a term applied to a number of different disorders, all having in common a genetic cause and the manifestation of weakness due to loss of the motor neurons of the spinal cord and brainstem. ... Werdnig-Hoffman disease (or Infantile spinal muscular atrophy, type I) is an autosomal recessive muscular disease. ... Kugelberg-Welander disease (or juvenile spinal muscular atrophy, type III) is an autosomal recessive muscular disease. ... Fazio Londe Syndrome is an inherited motor neuron disease found in children and young adults. ... The motor neurone diseases (MND) are a group of progressive neurological disorders that destroy motor neurones, the cells that control voluntary muscle activity such as speaking, walking, breathing, and swallowing. ... Amyotrophic Lateral Sclerosis (ALS, sometimes called Lou Gehrigs Disease, or Maladie de Charcot) is a progressive, usually fatal, neurodegenerative disease caused by the degeneration of motor neurons, the nerve cells in the central nervous system that control voluntary muscle movement. ... Progressive muscular atrophy (PMA) is a rare subtype of Motor neurone disease (MND) which affects only the lower motor neurones. ... Progressive bulbar palsy is a form of motor neuron disease characterized by dysfunction of the muscles controlled by the cranial nerves of the lower brain stem (the bulb) -- specifically, the glossopharyngeal nerve (IX), vagus nerve (X), and hypoglossal nerve (XII). ... Pseudobulbar palsy is a form of motor neuron disease which can be associated with paralysis. ... Primary lateral sclerosis (PLS) is a rare neuromuscular disease characterized by progressive muscle weakness in the voluntary muscles. ... In human anatomy, the extrapyramidal system is a neural network located in the brain that is part of the motor system involved in the coordination of movement. ... Neuroleptic malignant syndrome (NMS) is a life-threatening, neurological disorder most often caused by an adverse reaction to neuroleptic or antipsychotic drugs. ... This disease is believed to have been caused by a viral illness, stimulating degeneration of the nerve cells in the substantia nigra, leading to clinical parkinsonism. ... PKAN: Pantothenate Kinase-Associated Neurodegeneration Symptoms Pantothenate kinase-associated neurodegeneration (PKAN) is one of many forms of neurodegeneration, or brain deterioration . ... Progressive supranuclear palsy (PSP) (or the Steele-Richardson-Olszewski syndrome, after the Canadian physicians who described it in 1963 ) is a rare degenerative disorder involving the gradual deterioration and death of selected areas of the brain. ... Striatonigral degeneration refers to a form of multiple system atrophy involving the loss of connections between two areas of the brain, the striatum and the substantia nigra, which work together to ensure smooth movement and maintain balance. ... Dystonia is a neurological movement disorder in which sustained muscle contractions cause twisting and repetitive movements or abnormal postures. ... Torticollis, or wry neck, is a condition in which the head is tilted toward one side, and the chin is elevated and turned toward the opposite side. ... Meiges syndrome is a type of dystonia, also known as oral facial dystonia or hemifacial spasm, the main symptoms of which involve involuntary blinking and chin thrusting. ... A blepharospasm (from blepharo (eyelid) and spasm (uncontrolled muscle contraction)) is any abnormal tic or twitch of the eyelid. ... This article or section does not cite its references or sources. ... Myoclonus is brief, involuntary twitching of a muscle or a group of muscles. ... // Chorea sancti viti (Latin for St. ... Choreoathetosis is a combination of chorea and athetosis. ... Restless legs syndrome (RLS, or Wittmaack-Ekboms syndrome) is a condition that is characterised by an irresistible urge to move ones legs. ... Stiff person syndrome (SPS) (or occasionally, stiff-man syndrome) is a rare neurologic disorder of unknown etiology. ... A demyelinating disease is any disease of the nervous system in which the myelin sheath of neurons is damaged. ... Picks disease has two meanings that are often confused: 1) Pathology: Neurologists currently use the term Picks disease to mean specifically one of the pathological subtypes of frontotemporal lobar degeneration (FTLD). ... Alpers disease, also called progressive infantile poliodystrophy, is a progressive degenerative disease of the central nervous system that occurs in infants and children. ... Dementia with Lewy bodies is the second most frequent cause of hospitalization for dementia, after Alzheimers disease. ... Leighs disease, a form of Leigh syndrome, also known as Subacute Necrotizing Encephalomyelopathy (SNEM), is a rare neurometabolic disorder that affects the central nervous system. ... Devics disease, also known as Devics syndrome, neuromyelitis optica (NMO), or optic-spinal MS, is an autoimmune, inflammatory disorder in which a persons own immune system attacks myelin of the neurons of the optic nerves and spinal cord. ... Central pontine myelinolysis is a neurologic disease caused by severe damage of the myelin sheath of nerve cells in the brainstem, more precisely in the area termed the pons. ... Transverse myelitis is a neurological disorder caused by a loss of the myelin encasing the spinal cord, also known as demyelination. ... This article is about epileptic seizures. ... Focal seizures (also called partial seizures) are seizures which are characterized by: preserved consciousness in simple focal seizures impaired consciousness (dream-like) in complex focal seizures experience of unusual feelings or sensations sudden and inexplainable feelings of joy, anger, sadness, or nausea altered sense of hearing, smelling, tasting, seeing, or... Simple partial seizures are seizures which affect only a small region of the brain, often the temporal lobes and/or hippocampi. ... A complex partial seizure is an epileptic attack that involves a greater degree of impairment or alteration of consciousness/awareness and memory than a simple partial seizure. ... Generalised epilepsy is a form of epilepsy, a chronic neurological condition characterized by recurrent seizures, which are a result of abnormal activity in both sides of the brain. ... Tonic-clonic seizures (also known as Grand Mal Seizures, though this term is now discouraged and rarely used in a clinical setting) are a type of generalised seizure affecting the whole brain. ... Absence seizures are one of several kinds of seizures. ... Atonic seizures (also called drop seizures, drop attacks, or akinetic seizures), are a minor type of seizure. ... Benign familial neonatal convulsions (BFNC) is a rare autosomal dominant inherited form of epilepsy. ... Lennox-Gastaut syndrome (LGS), also known as Lennox syndrome, is a difficult to treat form of childhood-onset epilepsy, that most often appears between the second and sixth year of life and is characterized by frequent seizures and different seizure types and is often accompanied by mental retardation and behavior... West syndrome, otherwise known as infantile spasms, is an uncommon to rare and serious form of epilepsy in infants. ... Epilepsia partialis continua is a rare type of recurrent motor epileptic seizures that are focal (hands and face), and recur every few seconds or minutes for extended periods (days or years). ... Complex Partial Status Epilepticus (CPSE) is one of the non-convulsive forms of Status epilepticus, a rare form of epilepsy defined by its recurrent nature. ... A headache (cephalgia in medical terminology) is a condition of pain in the head; sometimes neck or upper back pain may also be interpreted as a headache. ... Familial hemiplegic migraine (FHM) is an autosomal dominant classical migraine subtype that typically includes hemiparesis (weakness of half the body) during the aura phase. ... Cluster headaches are rare, extremely painful and debilitating headaches that occur in groups or clusters. ... A vascular headache is a headache where blood vessel swelling or disturbance is causing the pain. ... Tension headaches, which were renamed tension-type headaches by the International Headache Society in 1988, are the most common type of primary headaches. ... A transient ischemic attack (TIA, often colloquially referred to as mini stroke) is caused by the temporary disturbance of blood supply to a restricted area of the brain, resulting in brief neurologic dysfunction that usually persists for less than 24 hours. ... Amaurosis fugax is a type of transient ischaemic attack (TIA). ... Transient global amnesia (TGA), is an anxiety-producing temporary loss of short-term memory. ... Cerebrovascular disease is damage to the blood vessels in the brain, resulting in a stroke. ... Middle cerebral artery syndrome is a condition where the blood supply from the middle cerebral artery is restricted, leading to a reduction of the function of the portions of the brain supplied by that vessel. ... Anterior cerebral artery syndrome is a condition where the blood supply from the anterior cerebral artery is restricted, leading to a reduction of the function of the portions of the brain supplied by that vessel. ... Posterior cerebral artery syndrome is a condition where the blood supply from the posterior cerebral artery is restricted, leading to a reduction of the function of the portions of the brain supplied by that vessel. ... Fovilles syndrome is caused by the blockage of the perforating branches of the basilar artery in the region of the brainstem known as the pons. ... Millard-Gubler syndrome is a syndrome of unilateral softening of the brain tissue arising from obstruction of the blood vessels of the pons, involving the sixth and seventh cranial nerves and fibers of the corticospinal tract, and is associated with paralysis of the abducens (including diplopia, internal strabismus, and loss... Lateral medullary syndrome (also called Wallenbergs syndrome) is a disease in which the patient has difficulty with swallowing or speaking or both owing to one or more patches of dead tissue (known as an infarct) caused by interrupted blood supply to parts of the brain. ... Webers Syndrome (superior alternating hemiplegia) is characterized by the presence of an oculomotor nerve palsy and contralateral hemiparesis or hemiplegia. ... There are very few or no other articles that link to this one. ... This article is about the sleeping disorder. ... Hypersomnia, also known as excessive daytime sleepiness (EDS), is excessive amount of sleepiness. ... Sleep apnea, sleep apnoea or sleep apnœa is a sleep disorder characterized by pauses in breathing during sleep. ... Ondines Curse, Congenital Central Hypoventilation Syndrome or primary alveolar hypoventilation, is a respiratory disorder that is fatal if untreated. ... For other uses, see Narcolepsy (disambiguation). ... Cataplexy is a medical condition which often affects people who have narcolepsy, a disorder whose principal signs are EDS (Excessive Daytime Sleepiness), sleep attacks, and disturbed nighttime sleep. ... Kleine-Levin Syndrome, or KLS, is a rare sleep disorder characterized by episodes of near-constant sleep and altered behavior. ... Circadian rhythm sleep disorders are a family of sleep disorders affecting the timing of sleep. ... Delayed sleep-phase syndrome (DSPS) is a chronic disorder of sleep timing. ... Advanced sleep phase syndrome (ASPS) is a sleep disorder in which patients feel very sleepy early in the evening (e. ... Normal pressure hydrocephalus (NPH) is a chronic type of communicating hydrocephalus whereby the increase in intracranial pressure (ICP) due to accumulation of cerebrospinal fluid (CSF) becomes stable and that the formation of CSF equilibrates with absorption. ... Idiopathic intracranial hypertension (IIH), sometimes called benign intracranial hypertension (BIH) or pseudotumor cerebri (PTC) is a neurological disorder that is characterized by increased intracranial pressure (ICP), in the absence of a tumor or other intracranial pathology. ... Encephalopathy literally means disease of the brain. ... Herniation, a deadly side effect of very high intracranial pressure, occurs when the brain shifts across structures within the skull. ... Cerebral edema (cerebral oedema in British English) is an excess accumulation of water in the intra- and/or extracellular spaces of the brain. ... Reyes syndrome is a potentially fatal disease that causes numerous detrimental effects to many organs, especially the brain and liver. ... An uncollapsed syrinx (before surgery). ... Syringobulbia is a medical condition when syrinxes, or fluid filled cavities, affect the brainstem. ... Spinal cord compression develops when the spinal cord is compressed by a tumor, abscess or other lesion. ... “Surgeon” redirects here. ... Insertion of an electrode during neurosurgery for Parkinsons disease. ... ICD-9-CM Volume 3 is a system of Procedural codes. ... For other uses of Skull, see Skull (disambiguation). ... Human brain In animals, the brain (enkephale) (Greek for in the skull), is the control center of the central nervous system, responsible for behavior. ... The meninges (singular meninx) is the system of membranes which envelop the central nervous system. ... A craniotomy is a surgical operation in which part of the skull (part of the cranium) is removed in order to access the brain. ... Decompressive craniectomy is a surgical procedure in which part of the skull is removed to allow a swelling brain room to expand without being squeezed. ... Look up Lobotomy in Wiktionary, the free dictionary. ... Hemispherectomy is a medical procedure where one hemisphere (half) of the brain is removed. ... Ventriculostomy is a neurological surgical procedure. ... Anterior temporal lobectomy is the complete removal of the anterior portion of the temporal lobe of the brain. ... The Spinal cord nested in the vertebral column. ... The spinal canal is the space in vertebrae through which the spinal cord passes. ... Cordotomy is a surgical procedure that disables selected pain-conducting tracts in the spinal cord, in order to achieve loss of pain and temperature perception. ... This article or section does not cite its references or sources. ... A discectomy is a surgical procedure where an extravasated segment of the intervertebral disc, which is causing pain by stressing the spinal cord or radiating nerves, is dissected. ... The term intervertebral disc annuloplasty indicates any procedure aimed at repairing the annulus of a bulging intervertebral disc before it herniates. ... An intervertebral disc arthroplasty is a neurosurgical procedure consisting in the replacement of a damaged intervertebral disc (previously removed through a discectomy procedure) with a synthetic prosthesis; it also goes under the common name of artificial disc replacement. Intervertebral disc arthroplasty is an alternative to vertebral fusion procedures, which also... A laminotomy is a neurosurgical procedure that removes part of a lamina of the vertebral arch in order to decompress the corresponding spinal cord and/or spinal nerve root. ... Laminectomy is a surgical procedure for treating spinal stenosis by relieving pressure on the spinal cord. ... A corpectomy is a surgical procedure that involves removing part of the vertebral body (Latin: corpus vertebrae, hence the name corpectomy), usually as a way to decompress the spinal cord and nerves. ... Foraminotomy is a medical operation used to relieve pressure on nerves that are being compressed by the intervertebral foramina, the passages through the bones of the vertebrae of the spine that pass nerve bundles to the body from the spinal cord. ... Vertebral fusion is the union of two adjacent vertebrae through the promotion of bone tissue to immobilise the joint. ... Vertebral fixation (also known as spinal fixation) is a neurosurgical procedure in which two or more vertebrae are anchored to each other through a synthetic vertebral fixation device, with the aim of reducing vertebral mobility and thus avoiding possible damage to the spinal cord and/or spinal roots. ... A patient undergoes a lumbar puncture at the hands of a neurologist. ... Cranial nerves Cranial nerves are nerves that emerge directly from the brain in contrast to spinal nerves which emerge from segments of the spinal cord. ... The peripheral nervous system or PNS, is part of the nervous system, and consists of the nerves and neurons that reside or extend outside the central nervous system--to serve the limbs and organs, for example. ... A ganglionectomy, also called a gangliectomy, is the surgical removal of a ganglion. ... Regional nerve blockade, or more commonly nerve block, is a general term used to refer to the injection of local anesthetic onto or near nerves. ... Anatomy and Physiology of the A.N.S. In contrast to the voluntary nervous system, the involuntary or autonomic nervous system is responsible for homeostasis, maintaining a relatively constant internal environment by controlling such involuntary functions as digestion, respiration, and metabolism, and by modulating blood pressure. ... GÅNGLÎÅ is a 1 man electronic grindcore band from Los Angeles California that began in August of 1999. ... Endoscopic thoracic sympathectomy (ETS) is a surgical procedure where certain portions of the sympathetic nerve trunk are burned, severed, removed or clamped. ... The process of cutting or to otherwise severe an axon. ... Hypophysectomy is the surgical removal of the pituitary gland, also called hypophysis. ... A vagotomy is a surgical procedure that is performed only in humans. ... For other uses, see System (disambiguation). ... Systems science is the science of complex systems. ... An example of a system: The nervous system. ... There are many definitions of complexity, therefore many natural, artificial and abstract objects or networks can be considered to be complex systems, and their study (complexity science) is highly interdisciplinary. ... Complex adaptive systems are special cases of complex systems. ... A conceptual system is a system that is comprised of non-physical objects, i. ... Cultural system refers to the functional interaction between the different elements of culture in a particular manner. ... The Lorenz attractor is an example of a non-linear dynamical system. ... An economic system is a particular set of social institutions which deals with the production, distribution and consumption of goods and services in a particular society. ... For other uses, see Ecological Systems Theory. ... In logic and mathematics, a formal system consists of two components, a formal language plus a set of inference rules or transformation rules. ... GPS redirects here. ... List of bones of the human skeleton Human anatomy is primarily the scientific study of the morphology of the adult human body. ... Information System (example) An Information System (IS) is the system of persons, data records and activities that process the data and information in a given organization, including manual processes or automated processes. ... World distribution of major legal traditions The three major legal systems of the world today consist of civil law, common law and religious law. ... A system of measurement is a set of units which can be used to specify anything which can be measured and were historically important, regulated and defined because of trade and internal commerce. ... The International System of Units (symbol: SI) (for the French phrase Syst me International dUnit s) is the most widely used system of units. ... A multi-agent system (MAS) is a system composed of several software agents, collectively capable of reaching goals that are difficult to achieve by an individual agent or monolithic system. ... In mathematics, a nonlinear system is one whose behavior cant be expressed as a sum of the behaviors of its parts (or of their multiples. ... An operating system (OS) is the software that manages the sharing of the resources of a computer and provides programmers with an interface used to access those resources. ... A physical system is a system that is comprised of matter and energy. ... A political system is a system of politics and government. ... The human eye is the first element of a sensory system: in this case, vision, for the visual system. ... See Social structure of the United States for an explanation of concepts exsistance within US society. ... This article is about the Solar System. ... For other uses, see Chaos Theory (disambiguation). ... Complex systems have a number of properties, some of which are listed below. ... For control theory in psychology and sociology, see control theory (sociology). ... For other uses, see Cybernetics (disambiguation). ... Holism in science, or Holistic science, is an approach to research that emphasizes the study of complex systems. ... Sociotechnical systems theory is theory about the social aspects of people and society and technical aspects of machines and technology. ... Systems biology is a term used very widely in the biosciences, particularly from the year 2000 onwards, and in a variety of contexts. ... System dynamics is an approach to understanding the behaviour of complex systems over time. ... Systems Ecology is a transdiscipline which studies ecological systems, or ecosystems. ... Systems engineering techniques are used in complex projects: from spacecrafts to chip design, from robotics to creating large software products to building bridges, Systems engineering uses a host of tools that include modeling & simulation, requirements analysis, and scheduling to manage complexity Systems Engineering (SE) is an interdisciplinary approach and means... Systems science is the science of complex systems. ... Systems theory is an interdisciplinary field of science. ... Russell Lincoln Ackoff (born 12 February 1919) is a Professor Emeritus of the Wharton School in operations research and systems theory. ... William Ross Ashby (September 6, 1903, London, England - November 15, 1972) was a British psychiatrist and a pioneer in the study of complex systems. ... Gregory Bateson (9 May 1904–4 July 1980) was a British anthropologist, social scientist, linguist and cyberneticist whose work intersected that of many other fields. ... Anthony Stafford Beer (September 25, 1926 - August 23, 2002) was a theorist in operational research and management cybernetics. ... Karl Ludwig von Bertalanffy (September 19, 1901, Vienna, Austria - June 12, 1972, New York, USA) was a biologist who was a founder of general systems theory--which he literally translated from the mathematization of Nicolai Hartmanns Ontology as stated by himself in his seminal work-- .An Austrian citizen, he... Kenneth E. Boulding Kenneth Ewart Boulding (January 18, 1910 - March 18, 1993) was an economist, educator, peace activist, poet, religious mystic, devoted Quaker, systems scientist, and interdisciplinary philosopher. ... British academic Peter Checkland is the developer of soft-systems methodology (SSM) in the field of systems thinking. ... Charles West Churchman (born August 29, 1913 Philadelphia, Pennsylvania, died March 21, 2004 Bolinas, California) was an American philospher in the field of management science, operations research and systems theory. ... He is a twat He was born in Vienna and died in Pescadero, California. ... Charles François is a Belgian citizen, born 1922 and retired from the Belgian Foreign Service since 1987. ... Jay Wright Forrester (born 14 July 1918 Climax, Nebraska) is an American pioneer of computer engineering. ... Ralph Waldo Gerard (7 October 1900, Harvey, Illinois - 17 February 1974) was an American neurophysiologist and behavioral scientist known for his wide-ranging work on the nervous system, nerve metabolism, psychopharmacology, and biological bases of schizophrenia [1]. // Gerard was born in Harvey, Illinois at the beginning of the 20th century. ... Debora Hammond down the Green River in Canyonlands National Park Debora Hammond is an American systems theorist, working as an Associate Professor professor Interdisciplinary Studies of the Hutchins School of Liberal Studies at the Sonoma State University. ... George Jiri Klir (1932 Prague, Czechoslovakia) is an Czech-American computer scientist and professor of systems sciences at the Center for Intelligent Systems at the Binghamton University in New York. ... Niklas Luhmann (December 8, 1927 - November 6, 1998) was a German sociologist, administration expert, and social systems theorist, as well as one the most prominent modern day thinkers in the sociological systems theory. ... Humberto Maturana (born September 14, 1928 in Santiago) is a Chilean biologist whose work crosses over into philosophy and cognitive science. ... Donella Dana Meadows (March 13, 1941 Elgin, Illinois, USA - February 20, 2001, New Hampshire) was a pioneering environmental scientist, a teacher and writer. ... Mihajlo D. Mesarovic (1928) is a Yugoslavian scientist, who was professor of Systems Engineering and Mathematics at Case Western Reserve University. ... Howard Thomas Odum (1924-2002), commonly known as H.T. Odum or Tom Odum, was an eminent American ecosystem ecologist and a professor at the University of Florida. ... Talcott Parsons Talcott Edgar Frederick Parsons (December 13, 1902–May 8, 1979) was for many years the best-known sociologist in the United States, and indeed one of the best-known in the world. ... Ilya Prigogine (January 25, 1917 – May 28, 2003) was a Belgian physicist and chemist noted for his work on dissipative structures, complex systems, and irreversibility. ... Anatol Rapoport (born May 22, 1911) is a Russian-born American Jewish, mathematical psychologist. ... Francisco Varela (Santiago, September 7, 1946 – May 28, 2001, Paris) was a Chilean biologist and philosopher who, together with his teacher Humberto Maturana, is best known for introducing the concept of autopoiesis to biology. ... JOHN N. WARFIELD The career of John Warfield has been described as passing through four phases: Phase 1: Electrical engineering faculty member: 1948-1965 Phase 2: Starting a systems science research career path: 1966-1980 Phase 3: Accruing evidence and developing components of systems science: 1980-2000 Phase 4: Aggregating... Norbert Wiener Norbert Wiener (November 26, 1894, Columbia, Missouri – March 18, 1964, Stockholm Sweden) was an American theoretical and applied mathematician. ...

  Results from FactBites:
 
nervous system: Definition and Much More from Answers.com (4534 words)
In humans, it consists of the central and peripheral nervous systems, the former consisting of the brain and spinal cord and the latter of the nerves, which carry impulses to and from the central nervous system.
The sympathetic nervous system responds to impending danger or stress, and is responsible for the increase of one's heartbeat and blood pressure, among other physiological changes, along with the sense of excitement one feels due to the increase of adrenaline in the system.
The parasympathetic nervous system, on the other hand, is evident when a person is resting and feels relaxed, and is responsible for such things as 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.
nervous system. The Columbia Encyclopedia, Sixth Edition. 2001-05 (1463 words)
Invertebrate animals show varying degrees of complexity in their nervous systems, but it is in the vertebrate animals (phylum Chordata, subphylum Vertebrata) that the system reaches its greatest complexity.
The central nervous system consists of the brain and spinal cord.
All of the fibers of the autonomic nervous system are motor channels, and their impulses arise from the nerve tissue itself, so that the organs they innervate perform more or less involuntarily and do not require stimulation to function.
  More results at FactBites »

 
 

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