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Question
With the help of a suitable diagram describe the structures of a neuron.
Solution
Nervous system consists of special cells called nerve cells or neurons. It has a main cell body called cyton. It gives out many processes called dendrites. From it a very long process is given out. It is called axon or nerve fibre.
The cell body has a nucleus. The dendrites get the message from the organs and send this message to the axon through the cell body. Then the axon sends the message to muscles to contrast or to the gland for secretion.
The neurons make contact with one another through their processes. The axon at its end branches and meets the dendrites of another neuron. The meeting point is called synapse. The message is passed on from one axon to the dendrites of another neuron. How the message goes ? It is like this:
Organ → Message goes to dnedrites → Cell body → Axon → Muscles or glands
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RELATED QUESTIONS
Distinguish between Cranial nerves and spinal nerves.
Draw neat and labelled diagrams of a myelinated neuron
Differentiate between Spinal nerves and Cranial nerves (number of nerves).
Fill in the blank:
The neurons carrying impulses from the brain to the muscles are called _______________________.
Mention the types of nerves found in humans.
Rearrange the following in correct sequence pertaining to what is given within brackets at the end.
Repolarisation - Depolarisation - Resting (polarised) (during conduction of nerve impulse through a nerve fibre)
Identify the ODD term in each set and name the CATEGORY to which the remaining three belong :
Axon, Dendron, Photon, Cyton
Which of the following statements is wrong regarding conduction of nerve impulse?
When the potential across the axon membrane is more negative than the normal resting potential, the neuron is said to be in a state of ______.
At the end of repolarization, the nerve membrane gets hyperpolarized. Why?
______ is the longest cell in our body.
Dendrons are the longest fibres that conduct impulses away from the cell body.
What are the gaps between adjacent myelin sheaths called?
The longest fibre on the cell body of a neuron is called ____________.
CNS is mostly made of ______
In the following diagram choose the correct labelling for A, B, C, D and E respectively.
Write one word for the following:
wave of electrical disturbance that sweeps over the nerve cell.
Which of the following structures is absent in nerve cells?
Name the following:
Three types of nerves.
Give reason:
Neurotransmitters are broken down by an enzyme just after passing an impulse from one neuron to the other.
