NERVOUS SYSTEM SPECIAL SENSE
SPINALCORD
Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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Dorsal
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Ventral
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Efferent
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Ascending
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Detailed explanation-1: -In contrast to the motor system, the cell bodies of the afferent sensory fibers lie outside the spinal cord, in posterior root ganglia.
Detailed explanation-2: -The dorsal roots contain sensory fibers from the skin, subcutaneous and deep tissues, and viscera. Primary afferent fibers of the dorsal roots are either myelinated or unmyelinated. Cutaneous, joint and visceral afferents are composed of myelinated A/, A and unmyelinated C fibers.
Detailed explanation-3: -Dorsal roots contain sensory axons which carry signals into the CNS. Ventral roots contains motor axons which carry signals from CNS-originating neurons to muscles and glands (Figure 17.1).
Detailed explanation-4: -The spinal ganglion contains the cell bodies of all sensory nerve fibers in the spinal nerve, , thus it has a crucial role in sensory transmission in the human body. More specifically, its main function is to relay the sensory nerve impulses from the periphery to the peripheral nervous system.
Detailed explanation-5: -The posterior/dorsal root contains afferent nerve fibres, which return sensory information from the trunk and limbs to the CNS. The cell bodies of the posterior root neurons are not located in the central grey matter in the spinal cord, but instead in a structure called the spinal/dorsal root ganglion.