The Cell Body

1491 Words Feb 3rd, 2016 6 Pages
1 - The Prototypical Neuron The neuron, also known as the nerve cell, is distinguished by several components: the soma, the axon, and the dendrites. The soma, or more commonly known as the cell body, is the semi-spherical central part of the neuron. In a typical neuron, it is about 20 um in diameter – and contains the same organelles that are found in all animal cells; a nucleolus, rough endoplasmic reticulum, smooth endoplasmic reticulum, Golgi apparatus, and mitochondria. With all of its inner components encased within the neuronal membrane. The neuronal membrane is an average of 5 nm thick, and greatly studded with various proteins; the function of a neuron is greatly regulated by the structure and components (proteins) of its …show more content…
The axon begins by extending away from the soma, with the base region being known as the axon hillock. The axon may then extend to various lengths (depending on the specific tissue/function that cell pertains to) ranging from less than a millimeter to over a meter; as well as splitting into numerous axon collaterals (axons that branch away from the original axon). As for the thickness of the axon, it ranges from less than a millimeter to 25 mm in diameter (in humans) - with the speed of electrical impulses (nerve impulse) directly proportional to the thickness of the axon. At the end of the axon, is the axon terminal or terminal bouton: which can be described as a swollen disk or button, where the axon comes into contact with another neuron, or another cell (e.g. muscle cell) by which information may be passed onto. This interface point is known as a synapse - with the end of the axon known as the presynaptic terminal; in this structure there are multiple synaptic vesicles (that average 50 nm in diameter) with various chemical signals (neurotransmitters) used for synaptic transmission (the process of information transfer). The membrane surrounding the synapse is heavily dense with proteins and ion channels, in order to receive and traffic the
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