BRAIN
SPINAL CORD
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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only one spinal nerve
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more than one spinal nerve
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Either A or B
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None of the above
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Detailed explanation-1: -Myotome Distribution. Most muscles in the limbs receive innervation from more than one spinal nerve root, and are hence comprised of multiple myotomes. Eg Biceps Brachii muscle flexes the elbow. It is innervated by the musculocutaneous nerve, which is innervated by C5, C6 and C7 nerve roots.
Detailed explanation-2: -Answer and Explanation: The answer is (A): all spinal nerves are mixed. All spinal nerves carry both motor and sensory fibers. Motor fibers exit the spinal cord via the ventral roots, whereas the sensory fibers enter the spinal cord through the dorsal roots.
Detailed explanation-3: -There are 31 pairs of spinal nerves and roots. Eight pairs of cervical nerves exit the cervical cord at each vertebral level. One member of the pair exits on the right side and the other exits on the left. The first cervical root exits above the C1 vertebra.