What is the purpose of chromatolysis?

Chromatolysis is a reactive change that occurs in the cell body of damaged neurons, involving the dispersal and redistribution of Nissl substance (rough endoplasmic reticulum and polyribosomes) in order to meet an increased demand for protein synthesis such as is required to regenerate axons.

What are Nissl bodies in neurons?

Nissl bodies (also called Nissl granules Nissl substance or tigroid substance) are discrete granular structures in neurons that consist of rough endoplasmic reticulum, a collection of parallel, membrane-bound cisternae studded with ribosomes on the cystosolic surface of the membranes.

What is nuclear eccentricity?

Nuclear eccentricity of zero means the centers of the nucleus and cell body are identical, while 100% eccentricity refers to nuclei in contact with the cell body perimeter.

Why do neurons have Nissl bodies?

In living neurons, they are visible in phase contrast microscopy. The Nissl bodies represent the protein-synthetic machinery of the cell. Key constituents are ribosomes; they disappear in toluidine blue preparations after treatment with RNAase.

What is the function of nissl’s granules?

Nissl’s granules are of the rough endoplasmic reticulum (RER) and contain free ribosomes. They are responsible for the synthesis of proteins which flow along the dendrites and the axon and replace the proteins which are broken down during cellular activity.

Is chromatolysis seen in multiple sclerosis?

Chromatolysis is, however, observed is part of many disease processes including multiple schlerosis, porphyria, pellagra, amyotrophic lateral sclerosis and poliomyelitis.

Why Nissl bodies are absent in axon?

– Axon cannot synthesize its protein hence it depends on soma. – The Soma also called a cell body of a neuron contains the nucleus and other structures common to living cells. – Small nerve cells of the central nervous system sometimes contain no Nissl bodies. – So, Nissl granules are absent in the axon.

What are Nissl bodies Mcq?

What are Nissl bodies? Explanation: Neurons are made up of three parts, i.e., cell body, dendrites, and axon. The cell body consists of ribosomes and a cluster of endoplasmic reticulum, which is known as Nissl bodies.

What is nuclear Pyknosis?

Pyknosis involves the shrinkage or condensation of a cell with increased nuclear compactness or density; karyorrhexis refers to subsequent nuclear fragmentation (Fig. 5-29, F). Pyknosis and karyorrhexis are degenerative changes that are often observed in nonseptic exudates.

Does nissl stain glia?

First, the Nissl technique stains the entire population of neurons and glial cell types in the same section. Second, the Nissl technique stains differentially all cell types of nervous tissue allowing distinction and identification of all cells.