Question

Which of the following contains the trigger zone of the neuron?

• A. Nissil’s granules
• B. Dendrites
• C. Axon
• D. Cyton

Answer 1

The correct option is C Axon

Cyton is the cell body (of neurons). It is also known as soma or perikaryon. It consists of the cytoplasm (neuroplasm). It has a centrally located nucleus.
Nissil’s granules are characteristic deeply stained particles present in the neuroplasm. They are also called tigroid bodies. They are irregular masses of RER and free ribosomes. They provide the grey shade to the grey matter. These are ribonucleoproteins. They are concerned with the synthesis of enzymes required for the formation of neurotransmitters (acetylcholine, dopamine etc).
Dendrites are short branched processes which receive impulse from adjacent neurons and transfer them to cyton.
Axon is the single long projection arising from the cell body. It conducts impulses from cyton to adjacent neurons. Plasma membrane of the axon is called axolemma. Axon hillock is the most sensitive part of the neuron. It is the starting point of the axon. It is the start point of the nerve impulse and hence is known as the trigger zone.