2. Cell process: Dendron and axon are cell process of neuron. Fine branches of Dendron called dendrites, contains some receptor points, so that Dendron receive the stimuli and produce centripetal conduction. Axon is the longest cell process of neuron. Axon is covered by axolemma. Part where axon arises from cyton called axon hillock. Cytoplasm of axon is called axoplasm which only contains neurofibrils and mitochondria. The terminal end of axon is branched and vesicular, called telodendria.

Some neurons are covered by layer of sphingomyelin (a phospholipid) called as myelin sheath or medulla. Myelin sheath is covered by thin cell membrane which is called as neurilemma or schwan cell. Myelin sheath act as insulator and prevent leakage of ions.

Structural classification of neuron
Neurons are grouped structurally according to the number of processes extending from cyton.

1. Unipolar neuron: Single process arises from cyton. e.g. nervous system of embryo. Some times this single process further divided into two processes. One of these act as axon while other act as dendrite. These kind of neurons are termed as pseudo-unipolar. e.g. Dorsal root ganglia of spinal cord and granule cells of olfactory bulbs.
2. Bipolar neuron: Two distinct process arise from cyton, an axon at one end and dendrite at another end. These type of neuron found in retina, olfactory epithelium, vestibular and cochlear ganglia.
3. Multipolar neuron: These types of neuron have one axon but many dendrons. Motor neurons and interneuron are multipolar.

Neurons of hydra and amacrine cell of retina have no definite cell process. These types of neurone are known as apolar neuron.

Functional classification of neuron
Functionally neurons can be divided into three categories based on the direction of nerve conduction.

1. Afferent or sensory neurons: Nerve conduction from receptors to the central nervous system.