What are the types of neurons based on their shapes?

There are four types of neurons based on their shapes: unipolar, bipolar, multipolar, and pseudounipolar neurons. 

1. Unipolar neurons have a single, long axon that extends from the cell body and then branches into two or more processes that extend in opposite directions. The central process extends toward the central nervous system and the peripheral process extends peripherally.
2. Bipolar neurons have two processes, an axon and a dendrite, which extend in opposite directions from the cell body. They are found in the retina of the eye and in the olfactory system.
3. Multipolar neurons have one axon extending from the cell body and several short and highly branched dendrites extending in all directions. They are the most abundant type of neuron in the body making up more than 99% of the total number. Multipolar neurons are found in the brain and spinal cord.
4. Pseudounipolar neurons share a few characteristics of both unipolar and bipolar neurons. They have a single axon that extends from the cell body similar to a unipolar neuron but this axon later branches into two distinct extensions, similar to a bipolar neuron. One extension is connected to dendrites and receives sensory information, while the other extension transmits the information it receives to the spinal cord.