Many Neurons fit the foregoing schema in every respect,, but there are also exceptions to most parts of it.. There are no neurons that lack a soma,, but there are neurons that lack dendrites,, and others that lack an axon.. Furthermore,, in addition to the typical axodendritic and axosomatic synapses,, there are axoaxonic (axon-to-axon) and dendrodendritic (dendrite-to-dendrite) synapses..

The key to neural function is the synaptic signaling process,, which is partly electrical and partly chemical.. The electrical aspect depends on properties of the neuron's membrane.. Like all animal cells,, the cell body of every neuron is enclosed by a plasma membrane,, a bilayer of lipid molecules with many types of protein structures embedded in it.. A lipid bilayer is a powerful electrical insulator,, but in neurons,, many of the protein structures embedded in the membrane are electrically active.. These include ion channels that permit electrically charged ions to flow across the membrane,, and ion pumps that actively transport ions from one side of the membrane to the other.. Most ion channels are permeable only to specific types of ions.. Some ion channels are voltage gated,, meaning that they can be switched between open and closed states by altering the voltage difference across the membrane.. Others are chemically gated,, meaning that they can be switched between open and closed states by interactions with chemicals that diffuse through the extracellular fluid.. The interactions between ion channels and ion pumps produce a voltage difference across the membrane,, typically a bit less than 1/10 of a volt at baseline.. This voltage has two functions: first,, it provides a power source for an assortment of voltage-dependent protein machinery that is embedded in the membrane; second,, it provides a basis for electrical signal transmission between different parts of the membrane..

Neurons communicate by chemical & electrical synapses in a process known as neurotransmission also called synaptic transmission.. The fundamental process that triggers the release of neurotransmitters is the action potential,, a propagating electrical signal that is generated by exploiting the electrically excitable membrane of the neuron.. This is also known as a wave of depolarization..

Brainalyst Technovision:: +91 99999 07074

A Neuron is a specialized type of cell found in the bodies of alleumetozans.. Only sponges and a few other simpler animals lack neurons.. The features that define a neuron are electrical excitability and the presence of synapses,, which are complex membrane junctions that transmit signals to other cells.. The body's neurons,, plus the Glial cells that give them structural and metabolic support,, together constitute the nervous system.. In vertebrates,, the majority of neurons belong to the central nervous system,, but some reside in peripheral ganglia,, and many sensory neurons are situated in sensory organs such as the retina and cochlea..

Although neurons are very diverse and there are exceptions to nearly every rule,, it is convenient to begin with a schematic description of the structure and function of a "typical" neuron.. A typical neuron is divided into three parts: the soma or cell body,, dendrites,, and axon.. The soma is usually compact; the axon and dendrites are filaments that extrude from it.. Dendrites typically branch profusely,, getting thinner with each branching,, and extending their farthest branches a few hundred micrometers from the soma.. The axon leaves the soma at a swelling called the axon hillock,, and can extend for great distances,, giving rise to hundreds of branches.. Unlike dendrites,, an axon usually maintains the same diameter as it extends.. The soma may give rise to numerous dendrites,, but never to more than one axon.. Synaptic signals from other neurons are received by the soma and dendrites; signals to other neurons are transmitted by the axon.. A typical synapse,, then,, is a contact between the axon of one neuron and a dendrite or soma of another.. Synaptic signals may be excitatory or inhibitory.. If the net excitation received by a neuron over a short period of time is large enough,, the neuron generates a brief pulse called an action potential,, which originates at the soma and propagates rapidly along the axon,, activating synapses onto other neurons as it goes.. This is called saltatory conduction..

Brainalyst Technovision: +91 99999 07074

Contd.....

All neurons are electrically excitable,, maintaining voltage gradients across their membranes by means of metabolically driven ion pumps,, which combine with ion channels,, embedded in the membrane to generate intracellular-versus-extracellular concentration differences of ions such as sodium,, potassium,, chloride and calcium.. Changes in the cross-membrane voltage can alter the function of voltage – dependent ion channels.. If the voltage changes by a large enough amount,, an all-or-none electrochemical pulse called an action potential is generated,, which travels rapidly along the cell's axon,, and activates synaptic connections with other cells when it arrives..

Neurons do not undergo cell division.. In most cases,, neurons are generated by special types of stem cells.. A type of glial cell,, called astrocytes (named for being somewhat star-shaped),, have also been observed to turn into neurons by virtue of the stem cell characteristic.. In humans,, neuro – genesis largely ceases during adulthood—but in two brain areas,, the hippocampus and olfactory bulb,, there is strong evidence for generation of substantial numbers of new neurons..

Brainalyst Technovision:: +91 99999 07074

Contd......

Motor Neurons receives signals from the BRAIN and Spinal Cord,, to cause muscle contractions,, and affect glandular outputs,, and inter-neurons which connect neurons to other neurons within the same region of the brain or spinal cord,, in neural networks..

A typical neuron possesses a cell body,, dendrites,, and an axon.. The term neurite is used to describe either a dendrite or an axon,, particularly in its undifferentiated stage.. Dendrites are thin structures that arise from the cell body,, often extending for hundreds of micrometres and branching multiple times,, giving rise to a complex "dendritic tree".. An axon is a special cellular extension that arises from the cell body at a site called the axon hillock and travels for a distance,, as far as 1 meter in humans or even more in other species.. The cell body of a neuron frequently gives rise to multiple dendrites,, but never to more than one axon,, although the axon may branch hundreds of times before it terminates.. At the majority of synapses,, signals are sent from the axon of one neuron to a dendrite of another.. There are,, however,, many exceptions to these rules: neurons that lack dendrites,, neurons that have no axon,, synapses that connect an axon to another axon or a dendrite to another dendrite,, etc..

Brainalyst Technovision:: +91 99999 07074

Neurons are the base cells of our BRAIN that processes and transmits the information through electrochemical signals.. These signals travels between neurons via very thin fibres also called synapses.. They make the neural networks to connect other cells.. They are the core components of our Central Nervous System,, which includes our BRAIN & Spinal Cord..

There are many types of Neurons performing a particular task or we can say specialized Neurons.. Sensory Neurons are responsible to react or coordinate with our sensory organs like touch,, light & so on.. Their task is to receive signals from sensory organs or from outer world & send electrochemical signals to our BRAIN & spinal Cord to complete the task.. 

Brainalyst Technovision:: +91 99999 07074