Which statement is true about the dorsal root?

Which statement is true about the dorsal root?

• A. Is part of the spinal cord only
• B. Carries sensory input
• C. Connects to autonomic neurons
• D. Carries motor output

Answer: (B)

The dorsal root functions as the sensory entry to the spinal cord. It carries afferent fibers that bring information from sensors in the body into the central nervous system. The cell bodies of these sensory neurons sit in the dorsal root ganglia just outside the spinal cord, which is why these fibers enter the spinal cord through the dorsal root. Because of this role, the dorsal root transmits sensory input rather than motor commands. Motor output travels the opposite way, leaving via the ventral root to innervate muscles. While visceral sensory information can travel through dorsal roots, the key idea is that the dorsal root’s primary job is carrying sensory signals into the CNS.

The dorsal root functions as the sensory entry to the spinal cord. It carries afferent fibers that bring information from sensors in the body into the central nervous system. The cell bodies of these sensory neurons sit in the dorsal root ganglia just outside the spinal cord, which is why these fibers enter the spinal cord through the dorsal root. Because of this role, the dorsal root transmits sensory input rather than motor commands. Motor output travels the opposite way, leaving via the ventral root to innervate muscles. While visceral sensory information can travel through dorsal roots, the key idea is that the dorsal root’s primary job is carrying sensory signals into the CNS.