II. Definitions
- Neuron
- Specialized conducting cell of the neurologic system which receives, conducts and transmits small electrical signals
- Building blocks of the nervous system
- Neurons are specialized into sensory Neurons and Motor Neurons
- Interneurons are a third type of Neurons that form interconnections between other Neurons
- Multiple Neurons are grouped into pathways
- Peripheral Nervous System: Nerves
- Central Nervous System: Tract, fasciculus, lemniscus, peduncle
- Synapse
- Connections between Neurons in which they communicate via chemical signals (Neurotransmitters)
- Neurologic Pathway
- Chain of communicating Neurons
- Neuraxis Tract (or fasciculus, peduncle or lemniscus)
- Bundle of axons in a pathway within the Central Nervous System (CNS)
- Nerve
- Bundle of axons in a pathway within the Peripheral Nervous System
- Neural Nucleus
- Group of Neuron cell bodies (soma) with attached group of axons (nerve tracts)
- Includes brain nucleii, Cranial Nerve nucleii, cerebellar nucleii and spinal cord nucleii
- Ganglia are the Peripheral Nerve versions of the CNS neural neuclei
III. Anatomy
- Images
- Background
- As with all cells, Neurons have a cell body (soma) with cytoplasm and a nucleus.
- Dendrites
- Tree-like extensions along the cell body that receive signals from other Neurons, or from Sensory Receptors
- Cell Body (Soma)
- Nucleus
- Cytoplasm (Perikaryon)
- Axon
- Transmits signal from cell body to axon terminals
- From the axon terminals, the signal is passed to other nerves via Neurotransmitters across Synapses
- Myelin Sheath
- Most axons are insulated with a thin layer (myelin) of cells to conserve and speed electrical transmission
- Myelinated axons appear as white matter (while Neuron cell bodies appear as gray matter)
- Transmits signal from cell body to axon terminals
-
Neurotransmitters
- Released from axon terminals to transmit a signal into Synapse (inter-Neuron space)
- Neuron types
- Sensory Neurons
- Motor Neurons
- Interneurons (interconnections between Neurons forming a pathway)
- Group of Neurons
- Peripheral Nervous System
- Nerves
- Central Nervous System (interchangeable names)
- Nerve Tract
- Fasciculus
- Lemniscus
- Peduncle
- Peripheral Nervous System
IV. Physiology: Nerve Impulse (Action Potential)
- Neurons are specialized cells capable of tranmsitting an electrical signal
- Neuron resting Membrane Potential is more positive on outside of cell than on inside (e.g. -60 mv difference)
- Depolarization
- Voltage gated electrical channels specific for Potassium and Sodium allow for electrical signal transmission
- Voltage channels are activated when there is a neutralization of resting Membrane Potential
- Membrane Potential decreases below a threshold (e.g. 15-35 millivolts or mv)
- Nerve Depolarization is an all-or-none phenomenon
- Nerve Impulse is only initiated if there is a sufficient Action Potential
- Voltage-Gated Sodium channels suddenly open
- Sodium rushes into Neuron, resulting in neutralization of resting potential and depolarization
- Inside and outside of Neuron may have minimal difference of charge at depolarization
- Voltage-Gated Calcium channels may also be involved
- Most common in cardiac Muscle (esp. Purkinje Fibers) and Smooth Muscle (uncommon in axons)
- As with Sodium, Calcium concentrations outside the cell are higher
- When Calcium channels open, Calcium rushes into the Muscle Cell
- However Calcium channels are slower than Sodium channels
- Results in an Action Potential plateau and a delayed repolarization/recovery
- Allows for a sustained, prolonged contraction of Muscles
- Signal spreads along the axon via contiguous regions, each depolarizing in turn
- Signal amplitude is fixed regardless of the stimulus strength
- However, stronger stimuli result in increased frequency of Action Potential impulses
- Myelin Sheath
- Unmyelinated Peripheral Nerve fibers
- Axon depolarizes continuously, via contiguous ion channels along its surface
- Myelinated Peripheral Nerve fibers
- Axons are insulated, wrapped with surrounding Schwann Cells
- Gaps between the Schwann Cells are known as Nodes of Ranvier
- Ion channels are not exposed where they are covered by overlying Schwann Cells
- Ion channels are only exposed at the Nodes of Ranvier
- Action Potentials must jump between Nodes of Ranvier (Saltatory Conduction)
- Results in most faster depolarization than with unmyelinated fibers
- Axons are insulated, wrapped with surrounding Schwann Cells
- Unmyelinated Peripheral Nerve fibers
- Repolarization
V. Physiology: Synapse
- Synapse is a connection between Neurons in which they communicate via chemical signals (Neurotransmitters)
- Nerve Impulse or Action Potential (see above)
- Nerve Impulse traverses the axon until it reaches the nerve terminals
- Nerve Impulse triggers nerve terminal release of Neurotransmitters from the pre-synaptic membrane
- Neurotransmitters pass into the inter-Neuron space (Synapse)
-
Neurotransmitters
- See Neurotransmitters
- Neurotransmitters act on the post-synaptic membrane of the adjacent Neuron's Dendrites
- Neurotransmitters lower the post-synaptic Membrane Potential of the next Neuron
- Target Neuron Stimulation requires the facilitation of multiple Action Potential triggers to fire
- Stimulation of many Synapses on the same target Neuron (spatial summation) or
- Rapid succession of Action Potentials over relatively few Synapses (temporal summation)
- Each Neuron may have up to 100,000 excitatory and inhibitory inputs that, summed, determine firing potential
- Excitatory Postsynaptic potential (EPSP) refers to sum of excitatory inputs (Action Potentials)
- Inhibitory Postsynaptic potential (IPSP) refers to sum of inhibitory inputs (Action Potentials)
VI. Physiology: Neuronal Networks
- Neurons are interconnected, often with thousands of inputs and outputs at a Synapse
- Neurotransmitters may have excitatory or stimulatory (positive) or inhibitory (negative) effects at the Synapse
- Patterns: Feedback Loops
- Negative Feedback
- Neuron A has excitatory effects at Neuron B
- Neuron A also has excitatory effects at Neuron C
- Neuron C inhibits Neuron A from firing
- Reverbation
- Neuron A has excitatory effects at Neuron B
- Neuron A also has excitatory effects at Neuron C
- Neuron C has excitatory effects at Neuron A, resulting in sustained firing
- Negative Feedback
- Patterns: Inter-Neuron
- Lateral Inhibition
- Neuron A, B and C lie in parallel to one another
- When Neuron B fires, it has excitatory effects on downstream Neurons
- However, Neuron B also has inhibitory effects on Neurons A and C
- Convergence
- Multiple Neurons input to a single Neuron output
- Divergence
- One Neuron has multiple Neuron outputs
- Neural Net
- Multiple Neurons interconnected with one another
- Lateral Inhibition
VII. Pathophysiology: Neurotransmission Disorders
- See Neurotransmitter
- Hyperexcitable Neurons with increased automaticity
- Excessive Neurotransmitter release and activity at post-synaptic receptors
- Insufficient Neurotransmitter release and activity at post-synaptic receptors
VIII. Images
-
Lewis (1918) Gray's Anatomy 20th ed (in public domain at Yahoo or BartleBy)
-
Lewis (1918) Gray's Anatomy 20th ed (in public domain at Yahoo or BartleBy)
-
Lewis (1918) Gray's Anatomy 20th ed (in public domain at Yahoo or BartleBy)
IX. References
- Goldberg (2014) Clinical Physiology, MedMaster, p. 36-7, 87-9
Calculation (FPnotebook.com: DrBits) Open in New Window
Images: Related links to external sites (from Bing)
Related Studies
| Definition (GO) | A process in which membrane potential cycles through a depolarizing spike, triggered in response to depolarization above some threshold, followed by repolarization. This cycle is driven by the flow of ions through various voltage gated channels with different thresholds and ion specificities. [GOC:dph, GOC:go_curators, GOC:tb, ISBN:978-0-07-139011-8] |
| Definition (CSP) | a rapid self-propagating change in the electrical potential across a neuron, gland, or muscle fiber membrane primarily due to a sudden influx of sodium ions followed by an efflux of potassium ions. |
| Definition (MSH) | Abrupt changes in the membrane potential that sweep along the CELL MEMBRANE of excitable cells in response to excitation stimuli. |
| Concepts | Cell Function (T043) |
| MSH | D000200 |
| English | Action Potential, Action Potentials, Potential, Action, Potentials, Action, action potential, action potentials |
| German | Aktionspotenziale, Aktionspotentiale |
| French | Potentiels d'action |
| Swedish | Aktionspotentialer |
| Czech | akční potenciály |
| Finnish | Aktiopotentiaalit |
| Russian | DEISTVIIA POTENTSIALY, ДЕЙСТВИЯ ПОТЕНЦИАЛЫ |
| Japanese | 活動電位 |
| Croatian | AKCIJSKI POTENCIJALI |
| Polish | Potencjały czynnościowe |
| Portuguese | Potenciais de Espiga, Potenciais de Espícula, Impulsos Nervosos, Potentiais de Pico, Potenciais de Ação |
| Italian | Potenziali d'azione |
| Dutch | Actiepotentiaal, Potentiaal, actie- |
| Spanish | Potenciales de Acción |
Ontology: Axon (C0004461)
| Definition (FMA) | Neurite which has as its direct parts an axon hillock, an axon proper, one or more axon collaterals and one or more axon terminals. |
| Definition (GO) | The long process of a neuron that conducts nerve impulses, usually away from the cell body to the terminals and varicosities, which are sites of storage and release of neurotransmitter. [GOC:nln, ISBN:0198506732] |
| Definition (UWDA) | Cell appendage of a neuron that consists of an axon hillock, an axon proper, axon collaterals and an axon terminal. |
| Definition (NCI) | A projection of a neuron that conducts electrical impulses away from the neuronal cell body. |
| Definition (MSH) | Nerve fibers that are capable of rapidly conducting impulses away from the neuron cell body. |
| Definition (CSP) | long fiber of a neuron, that carries efferent (outgoing) action potentials from the cell body towards target cells; each nerve cell has one axon, which can be over a foot long; in the peripheral nervous system, the larger (myelinated) axons are surrounded by a myelin sheath formed by concentric layers of plasma membrane of the Schwann cell. |
| Concepts | Cell Component (T026) |
| MSH | D001369 |
| SnomedCT | 60436000 |
| English | Axons, axon, neuraxons, axons, neuraxon, axone, Axon structure (cell structure), Axon structure, Axon structure (body structure), Axon |
| French | Axone, Prolongements axoniques, Axones |
| Swedish | Nervcellsutskott |
| Czech | axony |
| Finnish | Aksonit |
| Russian | AKSONY, АКСОНЫ |
| Croatian | AKSONI |
| Latvian | Aksoni |
| Polish | Neuryty, Aksony |
| Norwegian | Aksoner |
| Spanish | Axonas, axón, estructura del axón (estructura celular), estructura del axón (estructura corporal), estructura del axón, Axones |
| German | Achsenzylinder, Axone |
| Italian | Assoni |
| Dutch | Axon, Axonen |
| Portuguese | Axônios |
Ontology: Dendrites (C0011305)
| Definition (FMA) | Neurite which has as its direct parts a dendrite proper and a set of dendritic spines. |
| Definition (GO) | A neuron projection that has a short, tapering, often branched, morphology, receives and integrates signals from other neurons or from sensory stimuli, and conducts a nerve impulse towards the axon or the cell body. In most neurons, the impulse is conveyed from dendrites to axon via the cell body, but in some types of unipolar neuron, the impulse does not travel via the cell body. [GOC:dos, GOC:mah, GOC:nln, ISBN:0198506732] |
| Definition (UWDA) | Cell appendage of a neuron that consists of the dendrite proper and the dendritic spines. |
| Definition (NCI) | A long, branching outgrowth or extension from a neuron, that carries electrical signals from synapses to the cell body; any structure that resembles a dendrite. |
| Definition (MSH) | Extensions of the nerve cell body. They are short and branched and receive stimuli from other NEURONS. |
| Definition (CSP) | one of the threadlike extensions of the cytoplasm of a neuron, which typically branch into tree-like processes; in unipolar and bipolar neurons, there is a single dendrite, which proximally resembles an axon but branches distally; in multipolar neurons there are many short, branching dendrites; dendrites compose most of the receptive surface of a neuron; called also dendron, neurodendrite, and neurodendron. |
| Concepts | Cell Component (T026) |
| MSH | D003712 |
| SnomedCT | 90604005 |
| French | Prolongements dendritiques, Dendrite, Dendrites |
| Swedish | Nervcellsförgreningar |
| English | Dendritic, Dendrites, dendrite, dendrites, Dendrite, Dendrite (cell structure), Dendrite (body structure) |
| Czech | dendrity |
| Finnish | Dendriitit |
| Russian | DENDRITY, ДЕНДРИТЫ |
| Croatian | DENDRITI |
| Latvian | Dendrīti |
| Polish | Dendryty |
| Norwegian | Dendritter |
| Spanish | dendrita (estructura celular), dendrita (estructura corporal), dendrita, Dendritas |
| German | Dendriten |
| Italian | Dendriti |
| Dutch | Dendriet, Dendrieten |
| Portuguese | Dendritos |
Ontology: Membrane Potentials (C0025251)
| Definition (MSH) | The voltage differences across a membrane. For cellular membranes they are computed by subtracting the voltage measured outside the membrane from the voltage measured inside the membrane. They result from differences of inside versus outside concentration of potassium, sodium, chloride, and other ions across cells' or ORGANELLES membranes. For excitable cells, the resting membrane potentials range between -30 and -100 millivolts. Physical, chemical, or electrical stimuli can make a membrane potential more negative (hyperpolarization), or less negative (depolarization). |
| Definition (NCI) | The electrical potential difference across a plasma membrane. |
| Definition (CSP) | electrical potential difference across a biological, i.e., cell or organelle, or artificial membrane. |
| Concepts | Cell Function (T043) |
| MSH | D008564 |
| English | Potential, Membrane, Potential, Transmembrane, Potentials, Membrane, Potentials, Transmembrane, Transmembrane Potential, Transmembrane Potentials, Difference, Transmembrane Potential, Differences, Transmembrane Potential, Potential Difference, Transmembrane, Potential Differences, Transmembrane, Transmembrane Electrical Potential Difference, Transmembrane Potential Differences, Transmembrane Potential Difference, Membrane Potential, membrane potentials, transmembrane potential, membrane potential, potential resting, resting potential, resting membrane potential, rest membrane potential, Membrane Potentials |
| German | Transmembranpotentialdifferenz, Transmembrane elektrische Potentialdifferenz, Membranpotentiale, Transmembranpotentiale |
| French | Potentiels transmembranaires, Différence de potentiel transmembranaire, Différence de potentiel électrique transmembranaire, Potentiels de membrane |
| Swedish | Membranpotentialer |
| Czech | membránové potenciály |
| Finnish | Kalvojännitteet |
| Italian | Potenziali transmembrana, Differenza di potenziale transmembrana, Differenza di potenziale elettrico transmembrana, Potenziali di membrana |
| Russian | POTENTSIALY POKOIA, POKOIA POTENTSIALY, MEMBRANNYE POTENTSIALY, МЕМБРАННЫЕ ПОТЕНЦИАЛЫ, ПОКОЯ ПОТЕНЦИАЛЫ, ПОТЕНЦИАЛЫ ПОКОЯ |
| Croatian | Not Translated[Membrane Potentials] |
| Polish | Potencjały błonowe |
| Japanese | 静止電位, 膜電位, 膜内外電位, 静止膜電位 |
| Norwegian | Membranpotensial, Membranspenning |
| Dutch | Membraanpotentiaal, Membraanpotentialen, Rustpotentialen, Transmembraanpotentialen |
| Portuguese | Potenciais da Membrana, Potenciais Transmembrana |
| Spanish | Potenciales de la Membrana, Potenciales Transmembrana |
Ontology: Myelin Sheath (C0026973)
| Definition (GO) | An electrically insulating fatty layer that surrounds the axons of many neurons. It is an outgrowth of glial cells: Schwann cells supply the myelin for peripheral neurons while oligodendrocytes supply it to those of the central nervous system. [GOC:jl, NIF_Subcellular:sao-593830697, Wikipedia:Myelin] |
| Definition (FMA) | Cell appendage of a Schwann cell or an oligodendroctye which wraps around a zone of an axon; it is a shared part between the axon and the glial cell (Schwann cell or oligodenrocyte). |
| Definition (NCI_NCI-GLOSS) | The fatty substance that covers and protects nerves. |
| Definition (NCI) | A layer of phospholipids and protein found on neuronal axons. This structure acts as an electrical insulator that allows nerve impulses to travel faster by increasing the resistance and decreasing the capacitance over that found in unmyelinated nerve fibers. |
| Definition (MSH) | The lipid-rich sheath surrounding AXONS in both the CENTRAL NERVOUS SYSTEMS and PERIPHERAL NERVOUS SYSTEM. The myelin sheath is an electrical insulator and allows faster and more energetically efficient conduction of impulses. The sheath is formed by the cell membranes of glial cells (SCHWANN CELLS in the peripheral and OLIGODENDROGLIA in the central nervous system). Deterioration of the sheath in DEMYELINATING DISEASES is a serious clinical problem. |
| Concepts | Cell Component (T026) |
| MSH | D009186 |
| SnomedCT | 23879005 |
| English | Myelin Sheath, Myelin Sheaths, Sheath, Myelin, Sheaths, Myelin, Myelinated, medullary sheath, myelin sheath, myelin sheaths, myelin, Myelin sheath, Myelin sheath structure (cell structure), Myelin sheath structure, Myelin sheath, NOS, Myelin sheath structure (body structure), Myelin |
| Swedish | Myelinskida |
| Czech | myelinová pochva |
| Spanish | Vaina de Mielina, estructura de la vaina de mielina (estructura celular), estructura de la vaina de mielina (estructura corporal), estructura de la vaina de mielina, vaina de mielina |
| Finnish | Myeliinituppi |
| Russian | MIELINA SLOI, MIELINOVAIA OBOLOCHKA, MIELIN, МИЕЛИН, МИЕЛИНА СЛОЙ, МИЕЛИНОВАЯ ОБОЛОЧКА |
| Latvian | Mielīna apvalks |
| Polish | Osłonka mielinowa, Osłonka rdzenna |
| Croatian | Not Translated[Myelin Sheath] |
| Norwegian | Myelinskjede |
| Portuguese | Extrato Mielínico, Bainha de Mielina |
| German | Myelinscheide |
| Italian | Guaina mielinica |
| Dutch | Myelineschede, Schede, myeline- |
| French | Gaine de myéline |
Ontology: Myelinated nerve fiber (C0027750)
| Definition (NCI) | Axons of neurons encased in a lipoproteinaceous material called myelin. (MeSH) |
| Definition (MSH) | A class of nerve fibers as defined by their structure, specifically the nerve sheath arrangement. The AXONS of the myelinated nerve fibers are completely encased in a MYELIN SHEATH. They are fibers of relatively large and varied diameters. Their NEURAL CONDUCTION rates are faster than those of the unmyelinated nerve fibers (NERVE FIBERS, UNMYELINATED). Myelinated nerve fibers are present in somatic and autonomic nerves. |
| Concepts | Cell Component (T026) |
| MSH | D009413 |
| SnomedCT | 54115001 |
| English | Fiber, Myelinated Nerve, Fibers, Myelinated Nerve, Myelinated Nerve Fibers, Nerve Fiber, Myelinated, Nerve Fibers, Myelinated, myelinated nerve fibers, myelinated nerve fiber, Myelinated nerve fiber structure (body structure), Myelinated nerve fiber structure, Myelinated nerve fibre structure, Myelinated nerve fibre, Myelinated nerve fiber, NOS, Myelinated nerve fiber, Myelinated Nerve Fiber |
| French | Fibres myélinisées, Neurofibre myélinisée, Fibres myéliniques, Fibre nerveuse myélinisée, Fibres nerveuses myélinisées, Neurofibres myélinisées |
| Swedish | Nervtrådar, myeliniserade |
| Czech | nervová vlákna myelinizovaná |
| Spanish | Fibras Nerviosas Mielínicas, fibra mielínica de un nervio, estructura de la fibra mielínica de un nervio (estructura corporal), fibra nerviosa medulada, fibra nerviosa mielínica, estructura de fibra mielínica de nervio (estructura corporal), fibra medulada de un nervio, estructura de la fibra mielínica de un nervio, fibra mielínica de nervio, estructura de fibra mielínica de nervio, Fibras Nerviosas Mielinizadas |
| Finnish | Myeliinitupelliset hermosyyt |
| Russian | NERVNYE VOLOKNA MIELINIZIROVANNYE, A-VOLOKNA, NERVNYE VOLOKNA MIAKOTNYE, A-ВОЛОКНА, НЕРВНЫЕ ВОЛОКНА МИЕЛИНИЗИРОВАННЫЕ, НЕРВНЫЕ ВОЛОКНА МЯКОТНЫЕ |
| Croatian | ŽIVČANA VLAKNA, MIJELINIZIRANA |
| Latvian | Nervu šķiedras, mielinētās |
| Polish | Włókna nerwowe rdzenne, Włókna nerwowe osłonkowe |
| Norwegian | Nervefibre, myeliniserte, Nervetråder, myeliniserte, Myeliniserte nervefibre, Myeliniserte nervetråder |
| Portuguese | Fibras Nervosas Mielínicas, Fibras Nervosas Mielinadas, Fibras Nervosas Mielinizadas |
| German | Nervenfasern, myelinhaltige |
| Italian | Fibre nervose mielinate |
| Dutch | Gemyeliniseerde zenuwvezel, Vezel, zenuw-, gemyeliniseerde, Zenuwvezels, gemyeliniseerde |
Ontology: Nerve conduction function (C0027788)
| Definition (CSP) | movement of a nerve impulse along a single nerve. |
| Definition (MSH) | The propagation of the NERVE IMPULSE along the nerve away from the site of an excitation stimulus. |
| Concepts | Organ or Tissue Function (T042) |
| MSH | D009431 |
| SnomedCT | 22690006 |
| LNC | LP32240-1 |
| English | Conduction, Nerve, Conduction, Neural, Conductions, Nerve, Conductions, Neural, Nerve Conduction, Nerve Conductions, Neural Conduction, Neural Conductions, neural conduction, nerve conductions, nerve conduction, conduction nerve, Neural conduction, Nerve conduction, Nerve conduction (observable entity), Nerve conduction function |
| Swedish | Nervledning |
| Czech | nervové vedení |
| Spanish | Conducción Nerviosa, Conducción Neural, Conducción Neuronal, conducción nerviosa (entidad observable), conducción nerviosa, Conducción del Nervio |
| Finnish | Hermoimpulssin johtuminen |
| French | Conduction des influx nerveux, Propagation nerveuse, Conduction de l'influx nerveux, Conduction nerveuse |
| Italian | Conduzione nervosa, Conduzione neuronale |
| Russian | NERVNYKH IMPUL'SOV PROVEDENIE, VVEDENSKOGO TORMOZHENIE, ВВЕДЕНСКОГО ТОРМОЖЕНИЕ, НЕРВНЫХ ИМПУЛЬСОВ ПРОВЕДЕНИЕ |
| Japanese | 神経興奮伝導, 神経刺激伝導, 神経伝導 |
| Croatian | ŽIVČANA PROVODLJIVOST |
| Polish | Przewodnictwo nerwowe, Zjawisko Wedenskiego |
| German | Nervenleitung, Neurale Leitung |
| Dutch | Geleiding, zenuw-, Zenuwgeleiding |
| Portuguese | Condução Nervosa, Condução Neuronal |
Ontology: Neurons (C0027882)
| Definition (FMA) | Neural cell which has as its direct parts a cell body (soma) and one or more neurites; the neuron is the structural and functional unit of the nervous system. Examples: unipolar neuron, bipolar neuron, neuron of retina. |
| Definition (FMA) | Somatic cell which is dervied from the neuro-ectoderm or the neural crest. |
| Definition (MSHCZE) | Základní buněčné jednotky nervové tkáně. Každý neuron sestává z těla, axonu a dendritů - výběžků neuronu. Jejich účelem je přijímat, vést a přenášet impulsy v nervovém systému. |
| Definition (NCI_NCI-GLOSS) | A type of cell that receives and sends messages from the body to the brain and back to the body. The messages are sent by a weak electrical current. |
| Definition (NCI) | Any of the conducting cells of the nervous system. A typical neuron consists of a cell body, containing the nucleus and the surrounding cytoplasm (perikaryon); several short radiating processes (dendrites); and one long process (the axon), which terminates in twiglike branches (telodendrons) and may have branches (collaterals) projecting along its course. |
| Definition (MSH) | The basic cellular units of nervous tissue. Each neuron consists of a body, an axon, and dendrites. Their purpose is to receive, conduct, and transmit impulses in the NERVOUS SYSTEM. |
| Definition (CSP) | basic cellular units of nervous tissue; each neuron consists of a body, an axon, and dendrites and their purpose is to receive, conduct, and transmit impulses in the nervous system. |
| Concepts | Cell (T025) |
| MSH | D009474 |
| SnomedCT | 47220008 |
| English | Cell, Nerve, Cells, Nerve, Nerve Cells, nervous system cell, nerve unit, neurocyte, neurone, Neural cell, Nerve cell, Neurone, cells nervous system, cells neural, nerve cell, neurons, neural cell, nerve cells, neuron, Neuron, Neuron (cell), Neuron, NOS, Nerve Cell, Neural Cell, Neurocyte, Neurons |
| Swedish | Nervceller |
| Czech | neurony, nervové buňky |
| Finnish | Hermosolut |
| Italian | Cellule nervose, Neuroni |
| Russian | NEIRONY, NERVNYE KLETKI, NEIROTSIT, NEVROTSIT, НЕВРОЦИТ, НЕЙРОНЫ, НЕЙРОЦИТ, НЕРВНЫЕ КЛЕТКИ |
| Croatian | NEURONI |
| Latvian | Nervu šūnas, Neironi |
| French | Cellule nerveuse, Neurone, Cellules nerveuses, Neurones |
| Polish | Neurocyty, Komórki nerwowe, Neurony |
| Japanese | 神経細胞, ニューロン, ノイロン, 神経単位 |
| Norwegian | Nevroner, Nerveceller |
| Spanish | Células Neurales, neurona (célula), neurona, Neuronas, Células Nerviosas |
| Portuguese | Células Neurais, Células Nervosas, Neurônios |
| German | Nervenzellen, Neuronen |
| Dutch | Neuron, Neuronen, Zenuwcellen |
Ontology: Ranvier's Nodes (C0034667)
| Definition (MSH) | Regularly spaced gaps in the myelin sheaths of peripheral axons. Ranvier's nodes allow saltatory conduction, that is, jumping of impulses from node to node, which is faster and more energetically favorable than continuous conduction. |
| Definition (CSP) | constrictions occurring on myelinated nerve fibers at regular intervals of about one millimeter; at these sites the myelin sheath is absent and the axon is enclosed only by Schwann cell processes; Ranvier's nodes allow saltatory conduction, that is, jumping of impulses from node to node, which is faster and more energetically favorable than continuous conduction. |
| Definition (GO) | An axon part that is a gap in the myelin where voltage-gated sodium channels cluster and saltatory conduction is executed. [GOC:mh] |
| Concepts | Body Space or Junction (T030) |
| MSH | D011901 |
| SnomedCT | 34974004 |
| English | Nodes, Ranvier's, Ranvier Nodes, Ranvier's Nodes, Ranviers Nodes, Nodes of Ranvier, node of Ranvier, Node of Ranvier, Ranvier node, nodes of ranvier, node of ranvier, Ranvier's node, Ranvier's node (cell structure), Ranvier's node (body structure) |
| Swedish | Ranviers noder |
| Czech | Ranvierovy zářezy |
| Finnish | Ranvier'n kuroumat |
| Russian | RANV'E PEREKHVATY, PEREKHVATY UZLA, ПЕРЕХВАТЫ УЗЛА, РАНВЬЕ ПЕРЕХВАТЫ |
| Japanese | Ranvier絞輪, くびれ輪, ランビエ絞輪, ランヴィエ絞輪, 絞輪-ランビエ, 絞輪-Ranvier |
| Latvian | Ranvjē iežmaugas |
| Polish | Wcięcia mieliny, Przewężenia mieliny, Przewężenia Ranviera |
| Norwegian | Ranvierske innsnøringer |
| Spanish | Nudos de Ranvier, nódulo de Ranvier (estructura celular), nódulo de Ranvier (estructura corporal), nódulo de Ranvier, Nodos de Ranvier, Nódulos de Ranvier |
| Portuguese | Nós de Ranvier, Nodos de Ranvier, Nódulos de Ranvier, Nós Neurofibrosos |
| German | Ranvier-Schnürringe, Schnürringe, Ranvier- |
| Italian | Nodi di Ranvier |
| Dutch | Knoop van Ranvier, Knopen van Ranvier, Ranvier, knoop van |
| French | Noeud de Ranvier, Noeuds de Ranvier |
Ontology: Synapses (C0039062)
| Definition (MSHCZE) | Specializované spojení, na němž dochází ke styku neuronu s cílovou buňkou. U klasické synapse dojde k uvolnění chemického přenašeče (transmiteru) z měchýřku presynaptického zakončení neuronu, ten je rozstříknut přes synaptickou štěrbinu na aktivovaný receptor postsynaptické membrány cílové buňky. Cílem může být dendrit, buněčné tělo nebo axon jiného neuronu nebo specializovaná oblast svalu či sekreční buňka. Neurony mohou také komunikovat cestou přímého elektrického spojení prostřednictvím ELEKTRICKÝCH SYNAPSÍ. Existují i jiná nesynaptická spojení kromě chemické a elektrické signalizace, a to cestou mimobuněčně zprostředkované interakce. r |
| Definition (GO) | The junction between a nerve fiber of one neuron and another neuron or muscle fiber or glial cell; the site of interneuronal communication. As the nerve fiber approaches the synapse it enlarges into a specialized structure, the presynaptic nerve ending, which contains mitochondria and synaptic vesicles. At the tip of the nerve ending is the presynaptic membrane; facing it, and separated from it by a minute cleft (the synaptic cleft) is a specialized area of membrane on the receiving cell, known as the postsynaptic membrane. In response to the arrival of nerve impulses, the presynaptic nerve ending secretes molecules of neurotransmitters into the synaptic cleft. These diffuse across the cleft and transmit the signal to the postsynaptic membrane. [ISBN:0198506732] |
| Definition (NCI) | Specialized junctions at which a neuron communicates with a target cell. At classical synapses, a neuron's presynaptic terminal releases a chemical transmitter stored in synaptic vesicles which diffuses across a narrow synaptic cleft and activates receptors on the postsynaptic membrane of the target cell. The target may be a dendrite, cell body, or axon of another neuron, or a specialized region of a muscle or secretory cell. Neurons may also communicate through direct electrical connections which are sometimes called electrical synapses.(MeSH) |
| Definition (NCI_NCI-GLOSS) | The space between the end of a nerve cell and another cell. Nerve impulses are usually carried to the neighboring cell by chemicals called neurotransmitters, which are released by the nerve cell and are taken up by another cell on the other side of the synapse. The neighboring cell may be another nerve cell, a muscle cell, or a gland cell. |
| Definition (CSP) | specialized junctions at which a neuron communicates with a target cell; presynaptic terminals release a chemical transmitter stored in synaptic vesicles which diffuses across a narrow synaptic cleft and activates receptors on the postsynaptic membrane of the target cell; the target may be a dendrite, cell body, or axon of another neuron, or a specialized region of a muscle or secretory cell; do not confuse with the immunological synapse, see cross reference for that concept. |
| Definition (MSH) | Specialized junctions at which a neuron communicates with a target cell. At classical synapses, a neuron's presynaptic terminal releases a chemical transmitter stored in synaptic vesicles which diffuses across a narrow synaptic cleft and activates receptors on the postsynaptic membrane of the target cell. The target may be a dendrite, cell body, or axon of another neuron, or a specialized region of a muscle or secretory cell. Neurons may also communicate via direct electrical coupling with ELECTRICAL SYNAPSES. Several other non-synaptic chemical or electric signal transmitting processes occur via extracellular mediated interactions. |
| Concepts | Body Space or Junction (T030) |
| MSH | D013569 |
| SnomedCT | 69147006 |
| French | Synapse, Synapses, Jonction synaptique, Jonctions synaptiques |
| English | synaptic junction, Synapse, neuron junction, neuron-neuron junction, Synapsis, Synaptic junction, synapses, synapse, synapsis, Synapses, Synapse structure (body structure), Synapse structure |
| Swedish | Synapser |
| Czech | synapse |
| Finnish | Synapsit |
| Russian | SINAPSY, СИНАПСЫ |
| Japanese | 接合部-神経細胞間, シナプス, 神経細胞間シナプス |
| Croatian | SINAPSE |
| Latvian | Sinapses |
| Polish | Synapsy |
| Norwegian | Synapser, Synapse |
| Spanish | estructura de la sinapsis (estructura corporal), estructura de la sinapsis, sinapsis, Sinapsis |
| German | Synapsen |
| Italian | Sinapsi |
| Dutch | Synaps, Synapsen |
| Portuguese | Sinapses |
Ontology: Saltatory conduction (C0234093)
| Concepts | Cell Function (T043) |
| SnomedCT | 27750006 |
| English | Saltatory conduction, function, Saltatory conduction, Saltatory conduction, function (observable entity), Saltatory conduction (function) |
| Spanish | conducción saltatoria (entidad observable), conducción saltatoria (función), conducción saltatoria |
Ontology: Nerve fasciculus (C0549154)
| Concepts | Body Part, Organ, or Organ Component (T023) |
| SnomedCT | 123168002, 57592002 |
| English | Nerve fasciculus, Nerve bundle, Nerve fiber bundle, Neural fasciculus, nerve bundle, bundle nerve, bundles nerve, Nerve bundle (body structure), Nerve bundle -RETIRED- |
| Spanish | haz nervioso, haz nervioso (concepto no activo) |
Ontology: myelination (C0596991)
| Definition (GO) | The process in which myelin sheaths are formed and maintained around neurons. Oligodendrocytes in the brain and spinal cord and Schwann cells in the peripheral nervous system wrap axons with compact layers of their plasma membrane. Adjacent myelin segments are separated by a non-myelinated stretch of axon called a node of Ranvier. [GOC:dgh, GOC:mah] |
| Definition (CSP) | forming of the myelin sheath, the cylindrical covering that insulates the axons of some neurons; formed from the plasma membrane of Schwann cells or oligodendrocytes. |
| Concepts | Cell Function (T043) |
| English | myelination |
Ontology: Cell body of neuron (C0599444)
| Definition (FMA) | Cell body which consists of the plasma membrane and the cytoplasm surrounding the nucleus of the neuron. |
| Definition (GO) | The portion of a neuron that includes the nucleus, but excludes cell projections such as axons and dendrites. [GOC:go_curators] |
| Definition (UWDA) | Cell body which consists of the plasma membrane and the cytoplasm surrounding the nucleus of the neuron. |
| Definition (CSP) | the cell body of a neuron. |
| Definition (GO) | The portion of the cell soma (cell body) that excludes the nucleus. [GOC:jl] |
| Concepts | Cell Component (T026) |
| English | perikaryon, soma, Soma of neuron, Perikaryon, Cell body of neuron, neuronal cell body, neuronal cell soma, somas, cell body, body cell, bodies cell, neuron cell body, bodies cells, body cells, neural cell body, Cell Body |
Ontology: Nerve Impulses (C1720744)
| Concepts | Cell Function (T043) |
| MSH | D000200 |
| English | Impulse, Nerve, Impulses, Nerve, Nerve Impulses, Nerve Impulse |
| French | Influx nerveux |
| German | Nervenimpulse |
| Italian | Impulso nervoso |
| Czech | nervové impulzy, nervové impulsy |
Ontology: membrane depolarization (C1816453)
| Definition (GO) | The process in which membrane potential changes in the depolarizing direction from the resting potential, usually from negative to positive. For example, the initial depolarization during the rising phase of an action potential is in the direction from the negative resting potential towards the positive membrane potential that will be the peak of the action potential. [Wikipedia:Depolarization] |
| Concepts | Cell Function (T043) |
| English | membrane depolarization |
Ontology: Lemniscus of neuraxis (C2330117)
| Concepts | Body Part, Organ, or Organ Component (T023) |
| English | Neuraxis lemniscus, Lemniscus of neuraxis |
Ontology: Tract of neuraxis (C2330216)
| Concepts | Body Part, Organ, or Organ Component (T023) |
| English | Neuraxis tract, Tract of neuraxis |
Ontology: Peduncle of neuraxis (C2332863)
| Concepts | Body Part, Organ, or Organ Component (T023) |
| English | Peduncle of neuraxis, Neuraxis peduncle |
