In a cross-section of a spinal nerve, which structure would you identify as a cluster of sensory neuron cell bodies just outside the spinal cord?

In a cross-section of a spinal nerve, which structure would you identify as a cluster of sensory neuron cell bodies just outside the spinal cord?

• A. White matter
• B. Dorsal root ganglion
• C. Ventral root
• D. Anterior horn

Answer: (B)

Sensory neuron cell bodies are located in the dorsal root ganglion, a cluster that sits just outside the spinal cord along the dorsal root of a spinal nerve. These are the cell bodies of the pseudo-unipolar sensory neurons; their peripheral processes carry sensory information from receptors, while their central processes enter the spinal cord to synapse in the dorsal horn or brainstem. In cross-section, you’d recognize this as the bulge on the dorsal root before it merges with the spinal nerve. The other structures are not where cell bodies of sensory neurons reside: white matter is made up of myelinated axons with no neuron bodies; the ventral root carries motor (efferent) fibers; the anterior (ventral) horn contains motor neuron cell bodies within the gray matter of the spinal cord.

Sensory neuron cell bodies are located in the dorsal root ganglion, a cluster that sits just outside the spinal cord along the dorsal root of a spinal nerve. These are the cell bodies of the pseudo-unipolar sensory neurons; their peripheral processes carry sensory information from receptors, while their central processes enter the spinal cord to synapse in the dorsal horn or brainstem. In cross-section, you’d recognize this as the bulge on the dorsal root before it merges with the spinal nerve. The other structures are not where cell bodies of sensory neurons reside: white matter is made up of myelinated axons with no neuron bodies; the ventral root carries motor (efferent) fibers; the anterior (ventral) horn contains motor neuron cell bodies within the gray matter of the spinal cord.