What role does neurons play in the transmitting of electrochemical impulse?
451320
Just a word of confirmation- Neurons are not the only players in transmission- There is increasing evidence that glial cells can transmit is "spreading waves" by depolarization.
598126
The distribution of ions across a cell membrane produces a concentration gradient that can be used by the cell to do various kinds of work (i.e. power non-spontaneous reactions).  \n\nFor example, in mitochondria and certain aerobic bacteria, the gradient of H+ ions powers ATP synthase, and allows it to make ATP (an extremely important energy storage molecule).  \n\nIn other cells, the concentration gradients of ions can be used to facilitate active transport across the membrane by coupling an ion moving along it's concentration gradient with another molecule moving against it.\n\nIn neurons, the difference in the concentrations of ions inside and outside the cell creates a membrane polarity that allows the action potential (i.e. the nerve firing) to occur.  When the nerve is activated by a neurotransmitter or a direct external stimulus, sodium channels open, allowing Na+ to rush into the cell, making it positive relative to the external environment.  This change in polarity moves along the cell, and causes the cell to release specific neurotransmitters at the other end.\n\nIf the ions were distributed equally, none of the processes I just mentioned would work!
259472
ELECTRICAL IMPULSES sent down by "nodes" thru conducting pathways towards the atria and ventricles.......these atria and vents r made of muscles which contract on recievin the electrical shocks........and thats when the blood moves forward\nwhen their is no impulse being sent forward........the chambers of the heart relax and get filled with blood.....\n\njust waiting for the next impulse to come by and the heart contracts again\n\nthis goes on n on till u die!
467557
The direction of a nerve impulse is as follows: dendrite, cell body, axon. Dendrites are short extensions and axons are the longer ones. Once the impulse gets to the end of the axon, it travels through the synapse and then on to the dendrites of the following neuron. Within the neuron the impulse travels electrically with the resting potential changing to the action potential. In between neurons, through the synapse, the impulse is propagated chemically with the release of a neurotransmitter from the synaptic vesicles in the end of the axon . The neurotransmitter binds to receptors on the dendrite of the next neuron which starts the action potential there.
410329
Ok, Franko got it started-The action potential is propagated along the sensory axons, through the ulnar or other nerve (depending on exactly what part of your hand touched the stove), through the dorsal root ganglia (which is where the cell bodies for the sensory axon live) to the spinal cord.  There, they will release neurotransmitters at synapses with secondary sensory dendrites and cell bodies (which will send a signal on up the spinal cord to the brain) In addition, they will release neurotransmitters at synapses with interneurons, which synapse with motor neurons.  There motorneurons send axons to a number of muscles, such as the bicep.  A signal is generated at the motorneuron, sent down the axon, which then terminates on motor end-plates, which stimulate the muscle to contract, and thus pull the hand away.
71177
Neurotransmitters - What They Do . . .\n\nNeurotransmitters are small molecules whose function is to transmit nerve signals (impulses) from one nerve cell (neuron) to another. Neurotransmitters are chemical messengers which neurons use to tell other neurons that they have received an impulse. There are many different neurotransmitters - some trigger the receiving neuron to send an impulse and some stop it from doing so. See this simplified diagram of a neuron: \n\n\nNerve impulses always flow in one direction - from the branched extensions called dendrites, down the neuron to the presynaptic terminals. The join between the presynaptic terminals of one neuron and the dendrites of another is called the synapse. \n\nThe two neurons do not actually touch each other but are separated by a space called the synaptic cleft. \n\nWhen a nerve impulse arrives at a presynaptic terminal it causes neurotransmitters to be released into the synaptic cleft. The neurotransmitters then bind with special "postsynaptic receptors" in the dendrites of the receiving neuron. \n\nWhen a postsynaptic receptor receives a neurotransmitter it can either cause a nerve impulse to travel down the neuron or it can inhibit a nerve impulse depending on the neurotransmitter released. \n\nNeurotransmitters which propagate nerve impulses in the receiving neuron are called excitatory neurotransmitters. Those which inhibit nerve impulses are called inhibitory neurotransmitters. \n\nNeurotransmitters are sythesized in the cell body (the soma) and migrate down the axon to the presynaptic terminals. Here they are stored in little packets called vesicles which fuse with the synaptic membrane. When a depolarizing current (the action potential) is received, these vesicles release their contents into the synaptic cleft. \n\nNeurotransmitters activate receptors by "sticking" to them and thus preventing other neurotransmitters from activating them. Inactivation of the transmitter happens in one of three ways: \n\n\nReabsorption of the neurotransmitter into the neuron. This is known as reuptake. \n\nDestruction of the neurotransmitter with special chemicals called enzymes. This is known as enzymatic degradation. \n\nBy the neurotransmitter becoming deteched from the receptor and drifting out of the synaptic cleft. This is known as diffusion.\nSubstances that effect neurotransmission but are not neurotransmitters can be broadly divided into two categories - agonists and antagonists. \n\nAgonists make transmission of nerve impulses more likely. They do this in a number of ways including preventing reuptake (cocaine works this way). \n\nActually triggering the receptor themselves (nicotine works this way) \n\nAnd by making the receptor more responsive (a lot of anti-anxiety drugs work like this). \n\nAntagonists do the opposite - they interfere with nerve transmission across the synapse sometimes by blocking receptor sites (many spider and snake venoms work this way) \n\nAnd sometimes by preventing release of the neurotransmitter from the presynaptic terminal (many anti-psychotic drugs operate like this). \n\nThe following is an partial list of neurotransmitters, together with the sites in which they work: \n\nNeurotransmitters Group Neurotransmitter Region of Operation \nAcetylcholine Acetylcholine Central Nervous System (CNS), Peripheral Nervous System (PNS) and Autonomic Nervous System (ANS)  \nSerotonin SerotoninCNS and PNS \nAmino acids Glutamate, GammaAminobutyric Acid (GABA), Glycine, Aspartate  CNS \nHistamine Histamine Hypothalamus \nCatecholamines Norpinephrine, Epinephrine (Adrenalin) CNS and Sympathetic Nervous System \nNeuropeptides Endorphins (Enkephalins and Dynorphins), Substance P CNS \nDopamine Dopamine CNS \nNucleotides Adenosine, Adenosine Triphosphate (ATP) CNS, PNS and ANS \nNitric oxide Nitric oxide CNS
809192
Although the nervous system is very complex, there are only two main types of cells in nerve tissue. The actual nerve cell is the neuron. It is the "conducting" cell that transmits impulses and the structural unit of the nervous system. The other type of cell is neuroglia, or glial, cell. The word "neuroglia" means "nerve glue." These cells are nonconductive and provide a support system for the neurons. They are a special type of "connective tissue" for the nervous system.\nNeurons\n\nNeurons, or nerve cells, carry out the functions of the nervous system by conducting nerve impulses. They are highly specialized and amitotic. This means that if a neuron is destroyed, it cannot be replaced because neurons do not go through mitosis.
217155
Although serotonin is broadly distributed in the brain because it is a neurotransmitter, it is created in the cell body of the neuron.  Neurotransmitters are how brain cells (neurons) communicate with each other at the junction where the come in close contact. Neurotransmitters bridge the gap between neurons. They are produced in the body of the neuron where the cellular machinery needed to make them is located.  They are transported to the synapse  (the gap)by specific proteins inside the neuron or attached to the cell membrane of the neuron.  once released into the synapse specific proteins on the cell membrane can bind them and bring them back inside or degrade them.  Most are brought back into the neuron so they can be used again the next time the neuron needs them.
309339
Transmission of the signal requires a complete cellular membrane, because the signal is a waveform traveling along that membrane.  Cutting the axon (which is done in studying axonal regrowth and regeneration) disrupts the membrane integrity, thus no signal can pass this point.  In some neurons, the axon can travel as much as 3 feet, and damage done at the proximal end of the axon can take months to regrwo.  However, if you are talking about loss of the presynaptic terminal only (as occurs in some diseases), then reconnection could occur within hours or days.
117658
Interesting. The brain is a bundle of neurons, but it has no "feeling" itself.  An electrode inserted into the brain is painless.
471751
a synapse is also called a junction. it's a space between neurons where neurotransmitters are released. to transmit information from one neuron to another, the neurotransmitters travel through the cell body of the neuron and are released though the axon. after chillin in the synaptic gaps they are received from the dendrite of another neuron. i'm assuming you know what an action potential is? anyway as it travels through the nueron it can't really leave so it lets the neurotransmitters escape and go to another neuron. if the action potential is great enough you react to the stimulus. if it doesn't reach the threshold then you don't.
736048
I'd agree that it is unlikely to cross the BBB due to the number of charged group. It is a peptide that contains several amino acids with adequate pKa values to be charged at physiological pH.\n\nIt doesn't need to enter cells to have an effect. Its primary mechanism of action is to prevent Na+ ions entering through voltage-gated Na+ channels. Particularly those in neurons. It sits over the pore of the channel which is, of course, extracellular. It needs only to be distributed in the plasma and interstitial space.\n\nInterestingly, many of the VGSCs in the dorsal root ganglia are TTX-resistant.
124440
Well, our professor was telling us about the possibility of applying stem cell technology in this area. Embryonic stem cells when given the right environmental cues can develop into neurons. Alternatively, Schwann cells which are the ones that wrap around the axons and allow for conduction can also be generated from embryonic stem cells. Hope that helps.
550392
yes they have but very small effect , since nerve impulses are electric messages thus they are effected!!!
458577
The Dendrites receive the information transmitted by action potentials from other neurons.  The Axon conducts an action potential to the synapse to pass on to other neurons.  In other words,  Dendrites receive information and the Axon sends information.  \n\nA neuron has many dendrites but only one axon.\n\nHope this helps!
670939
No, that's not right.  The movement of sodium and potassium across the membrane carries the action potential along the neurite, but not between neurons.  Neurotransmitters-released by one neurons (usually at an axon terminal) crosses the synapse, and binds with specific receptors (usually on the dendrite or axon hillock). Once it binds, it usually opens ligand-gated sodium channels.  \n\nYou asked the name of the chemical, but it's actually a class of chemicals, not one, called neurotransmitters.  Common ones are glutamate, acetylcholine, seretonin, epinephrine and dopamine, but there are literally dozens of them.
462235
Depends on the function. For example, voluntary movement requires central nervous system and musculo-skeletal system working together, i.e. impulse arises from the motor cortex in the brain, travels through the central/peripheral nervous system to the muscle(s) needed to allow for specific movement, feedback from sensory receptors go back to brain to finetune movement accordingly. (a very basic explanantion!)