Question

If the dorsal root of the spinal cord is broken down then its effect is
(a) No effect on impulse
(b) Impulse is transmitted fast
(c) Impulse is transmitted but slowly
(d) No impulse is transmitted from the receptor

Answer 1

It carries sensory information (sensations) from the body and some from the head to the central nervous system (CNS) via afferent fibers, and it performs the initial processing of this information. It comprises neurons whose descending axons mediate autonomic control for most of the visceral functions.

Complete answer:
For entering other areas of the body, the dorsal root is the main bundle of nerve fibers that branch off from the spinal cord. This combines with the ventral root to form the spinal nerve. and becomes the afferent sensory root and is responsible for carrying and transmitting the sensory information from the body to the brain for processing the signals by the brain. If the dorsal root is broken, then the transfer of information will not be possible.

Additional Information: The spinal cord has four different regions: the cervical, thoracic, lumbar, and sacral regions. The different cord regions can be visually distinguished from each other. The cord is segmentally organized. There are 31 segments and are defined by 31 pairs of nerves exiting the cord. These nerves are divided into 8 cervicals, 12 thoracics, 5 lumbar, 5 sacral, and 1 coccygeal nerve. The dorsal and ventral roots enter and leave the vertebral column individually through intervertebral foramen at the vertebral segments corresponding to the spinal segment.
So, the correct answer is ‘No impulse is transmitted from the receptor’.

Note: A transverse section of the adult spinal cord shows white matter in the periphery, gray matter inside, and a tiny central canal filled with CSF at its center. The ependymal layer surrounding the canal is a single layer of cells. Encompassing the ependymal layer is the gray matter – a region containing cell bodies – shaped like the letter “H” or a “butterfly”.