Human Anatomy, Part 1 - K. A. Dyubenko, A. K. Kolomiysev, Yu. B. Chaykovsky 2002

General Part
Structure of the Human Body
Tissues - Nervous Tissue - Internal Structure of a Neuron

The specific Structural Features of Nerve Cells (Fig. 11) include:

- the presence of basophilic clumps in the Cytoplasm, known as Nissl substance;

- the presence of fibrillar structures (neurofibrils) in both The Cell body and the processes of neurocytes.

Under light Microscopy of preparations stained with basic Dyes, Nissl's basophilic substance appears as clusters of granules accumulated within the cell body and the initial segments of dendrites, while being absent in the axon. Transmission Electron microscopy of neurocytes reveals that these clumps consist of densely packed anastomosing tubules and cisterns of the granular Endoplasmic reticulum, interspersed with numerous free Ribosomes and Polysomes. Thus, Nissl substance represents a highly developed protein-synthesizing machinery, reflecting the intensely high rate of Protein Synthesis in nerve cells.

Neurofibrils form a three-dimensional network within the neurocyte cytoplasm, whereas in the processes, they run predominantly parallel to the long axis. Neurofibrils are composed of microtubules with a diameter of 20-30 nm and neurofilaments (microfilaments) belonging to the so-called Intermediate filaments, measuring 6-10 nm in diameter, which provide structural support. Neurofilaments play a crucial role in Intracellular Transport processes within the cell body and its processes, and constitute its Cytoskeleton.

Despite sharing General Structural Features, Neurons are highly specialized. Their function and Structure are determined by their Location within The Nervous system and, unlike most other cells, they are non-interchangeable. (For more detailed information, please refer to Histology textbooks).



Last update: 08/08/2026

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