Question

Assertion :

All motor neurons are efferent neurons.

Reason:

Motor neurons conduct nerve impulses from the spinal cord to the brain.

• A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
• B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
• C. Assertion is correct but Reason is incorrect
• D. Both Assertion and Reason are incorrect

Answer 1

The correct option is C Assertion is correct but Reason is incorrect

The neurons and nerve fibre which conduct nerve impulse from the Central Nervous System (CNS) to the peripheral organs and tissues are called efferent neurons and efferent nerve fibre respectively. Some of the neurons and nerve fibres conduct nerve impulses to the muscles and gland to stimulate or inhibit their activities. Many of these nerve fibres cause movements of muscles. So, such neurons and nerve fibres are known as motor neurons and motor nerve fibres, respectively.

The motor nerve fibres are the axons of motor neurons. All motor neurons are efferent neurons because they conduct impulses from the CNS to the peripheral tissues viz, muscles and gland. The nerve fibres which reach nerve impulses to the eye muscles to control their movements are motor fibres; so also are the fibres carrying impulses to the salivary glands and controlling their secretion. The nerve impulses are conducted from the spinal cord to the brain by ascending nerve tracts which are the bundles of nerve fibres ascending along the white matter of the spinal cord.

So the correct option is C.