Nissl bodies are mainly composed of
Nucleic acids and SER
DNA and RNA
Proteins and lipids
Free ribosomes and RER
As we learnt in
Structure of neuron -
bodies called Nissl’s granules. Short fibres which branch repeatedly and project out of the cell body also contain Nissl’s granules and are called dendrites. These fibres transmit impulses towards the cell body. The axon is a long fibre, the distal end of which is branched. Each branch terminates as a bulb-like structure called synaptic knob which possess synaptic vesiclescontaining chemicals called neurotransmitters. The axons transmit nerve impulses away from the cell body to a synapse or to a neuro-muscular junction. Based on the number of axon and dendrites, the neurons are divided into three types, i.e., multipolar (with one axon and two or more dendrites; found in the cerebral cortex), bipolar (with one axon and one dendrite, found in the retina of eye) and unipolar (cell body with one axon only; found usually in the embryonic stage). There are two types of axons, namely, myelinated and nonmyelinated. The myelinated nerve fibres are enveloped with Schwann cells, which form a myelin sheath around the axon. The gaps between two adjacent myelin sheaths are called nodes of Ranvier.
- wherein
Nissl granules are responsible for protein synthesis and are present in the cyton and even extend into the dendrite of the neuron. Nissl granules are composed of free ribosomes and RER.
Option 1)
Nucleic acids and SER
This is incorrect.
Option 2)
DNA and RNA
This is incorrect.
Option 3)
Proteins and lipids
This is incorrect.
Option 4)
Free ribosomes and RER
This is correct.