Zoology, Animal Physiology

Paper : 06 Animal Physiology
Module : 01 General organization and classification of neuron




Development Team

Principal Investigator : Prof. Neeta Sehgal
Department of Zoology, University of Delhi


Co-Principal Investigator : Prof. D.K. Singh
Department of Zoology, University of Delhi


Paper Coordinator : Prof. Rakesh Kumar Seth
Department of Zoology, University of Delhi


Content Writer : Dr. Anju Jain1, Dr. KP Mishra2, Dr. Sarita Nanda1
1Daulat Ram College, University of Delhi
2 Defence Institute of Physiology and Allied Sciences, Delhi

Content Reviewer : Dr. Tanushri Saxena
Shraddhanand College, University of Delhi




Animal Physiology
ZOOLOGY
General Organization and Classification of neuron

, Description of Module

Subject Name ZOOLOGY

Paper Name Zool 006 Animal Physiology

Module Name/Title Organization and Evolution of Nervous System

Module Id M01: General Organization and Classification of neuron

Keywords Affector, Effector, Neuron, Glial cells, Unipolar, Bipolar,
Multipolar, Astrocytes, Oligodendrocytes, Microglia, Nissl
Bodies, Dendrites, Sensory neuron, Motor neuron, Schwann Cells,
Satellite cells, Ependymal cell


Contents
1. Learning Outcomes
2. Introduction
3. Neuron as the Basic Unit of Nervous System
4. Discovery of Neurons
5. Classification of neurons
6. Glial Cells: supporting cells
7. Identification of Neurons by Various Techniques
8. Neuronal Stem Cells (NSCs)
9. Conclusion
10. Summary




Animal Physiology
ZOOLOGY
General Organization and Classification of neuron

, 1. Learning Outcome

This chapter will help you to learn about the following:
 Different parts of the brain
 The characteristics of Neurons
 History of discovery of the brain cells
 Classification strategies of Neurons
 Characteristics of the supporting cells of the brain
 The various techniques which are used in study of the brain
 The stem cells present in the brain tissue.


2. Introduction

Brain, the most complex part of the body communicates with each and every other body parts
through a well-developed and essential electrical wiring known as nervous system which
includes both the central nervous system (CNS) and the peripheral nervous system (PNS).
The central nervous system is the main integration and command centre of body and is made
up of the and spinal cord where PNS connects the CNS to different effector organs of body
and is divided into two subdivisions, somatic nervous system (SNS) and autonomic nervous
system (ANS) (Fig.1). Along with that recent researches also revealed the importance of
enteric nervous system (ENS) or intrinsic nervous system as one of the major divisions of the
nervous system. It includes a mesh-like system of neurons that mainly governs the function
of the gastrointestinal tract. The ENS again includes two plexuses, the submucosal and the
myenteric with their own functions.

The cellular building blocks of the entire nervous system are nerve cells, called neurons, and
supporting cells called glial cells. The human brain is composed of almost 100 billion
of electrically excitable neurons and 10 times as many glial cells (Herculano-Houzel S.
2009). Neurons are specialized for electrical and chemical signaling over long distances.
Glial cells, in contrast to nerve cells, are not capable of transmission of electrical signaling;
thereby the neuron is the only functional unit of the nervous system. Current evidences




Animal Physiology
ZOOLOGY
General Organization and Classification of neuron