Neurons Classification

Neurons are classified in two main ways:

• Structural Classification
• Functional Classification

Structural Classification

Neurons differ based on the number of processes attached to the cell body:

1. Unipolar Neurons

   • Single process projecting from the cell body.
   • Sometimes referred to as pseudo-unipolar due to branching of the single process.

2. Bipolar Neurons

   • Two processes extending from the cell body.

3. Multipolar Neurons

   • More than two processes extending from the cell body.

Key Points

• All structural types have the same functional parts, regardless of appearance:
  • Reception region: Receives incoming information.
  • Conductive region: Generates and conducts the action potential.
  • Transmission region: Conveys the action potential to the next cell across the synapse.

Functional Classification

Neurons are classified based on the direction of information flow:

1. Sensory Neurons

   • Carry information into the central nervous system (CNS).
   • Typically, they are unipolar neurons.

2. Interneurons

   • Contained entirely within the CNS.
   • Act as the internal wiring of the CNS.
   • Are the most numerous and do not fit the three common structural categories.

3. Motor Neurons

   • Carry information from the CNS out to the body.
   • Typically, they are multipolar neurons.

Additional Information

• Bipolar Neurons
  • Most rare.
  • Found in special senses (e.g., retina).
• Interneurons
  • Have diverse structures and are crucial for internal connections within the CNS.