Q23 of 54 Page 49

Assertion (A): All spinal nerves are mixed nerves.

Reason (R): Each spinal nerve has a sensory root and a motor root.

Mixed nerves are those nerves which contain both the sensory and motor neurons. Spinal nerves are one of them which can receive stimuli through sensory neurons and show effector functions using motor neurons.

Since both ‘A’ and ‘R’ are true and ‘R’ explains ‘A’. Therefore correct option is (i).

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21

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a) Axon b) Terminal branches


c) Cyton d) Dendrites


The correct pathway of a nerve impulse through these parts is _____________.

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For minor surgeries in the body, doctors administer local anaesthesia to a part of the body so that the pain will not be felt by the patient. At which part, do you think, the nerve impulse is being arrested due to the effect of anaesthesia?

 1

Name the two systems which help in the control and co-ordination of metabolic activities.

Write any one difference between them.

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Differentiate medullated neurons from non-medullated neurons. Where are they found in the nervous system?