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The neuron's dendrites are effectively branching extensions of the cell body. Collectively, these branching structures of the dendrites is known as the "dendritic tree". The dendritic tree is the site where input to the neuron occurs via synapses with axons from other nerve cells. In most cases nerve impulses travel from other nerve cells to the cell body and are then conducted along the nerve cell's own axon to other cell bodies. However, dendrites themselves are unable to propagate nerve impulses in the manner of axons as dendrites are unable to secrete [[Neurotransmitters_-_Anatomy_%26_Physiology|neurotransmitters]]. Similarly axons do not possess the chemoreceptors that are found within the dendrites and are therefore unable to receive nerve impulses. Nerve impulses are therefore conducted in one direction only.

The neuron's dendrites are effectively branching extensions of the cell body. Collectively, these branching structures of the dendrites is known as the "dendritic tree". The dendritic tree is the site where input to the neuron occurs via synapses with axons from other nerve cells. In most cases nerve impulses travel from other nerve cells to the cell body and are then conducted along the nerve cell's own axon to other cell bodies. However, dendrites themselves are unable to propagate nerve impulses in the manner of axons as dendrites are unable to secrete [[Neurotransmitters_-_Anatomy_%26_Physiology|neurotransmitters]]. Similarly axons do not possess the chemoreceptors that are found within the dendrites and are therefore unable to receive nerve impulses. Nerve impulses are therefore conducted in one direction only.

===Axon (Nerve Fibre)===

===Axon (Nerve Fibre)===

The axon is a very fine projection that can measure up to thousands of time the soma diameter in length. The axon carries nerve signals away from the soma. The structure and function of the axon is very similar between the CNS and the PNS. This has been covered in detail within the PNS Structure and Anatomy page so for further information please click [[PNS_Structure_-_Anatomy_%26_Physiology#Structure|here]].

The axon is a very fine projection that can measure up to thousands of time the soma diameter in length. The axon carries nerve signals away from the soma. The structure and function of the axon is very similar between the CNS and the PNS.

This has been covered in detail within the PNS Structure and Anatomy page so for further information please click [[PNS_Structure_-_Anatomy_%26_Physiology#Structure|here]].

 

===Glial Cells===

===Glial Cells===

Glial cells make up approximately 50% of the volume of the nervous system and the number of glial cells out-numbers the nerve cells by a factor of ten to one. The primary function of glial cell is to provide support to the neuronal cells. There are several different types of glial-style cell; in the PNS these are referred to as '''Schwann cell''' whilst in the CNS they are referred to as '''Oligodendrocytes'''.  

Glial cells make up approximately 50% of the volume of the nervous system and the number of glial cells out-numbers the nerve cells by a factor of ten to one. The primary function of glial cell is to provide support to the neuronal cells. There are several different types of glial-style cell; in the PNS these are referred to as '''Schwann cell''' whilst in the CNS they are referred to as '''Oligodendrocytes'''.