Chapter 13 - Section 13.2 - The Spinal Nerves - Before You Go On - Page 495: 7

The neurosomas, also known as cell bodies or soma of neurons, within the spinal cord are not located in the posterior or anterior roots themselves. Instead, they are found in specific regions of the spinal cord. 1. **Neurosomas of the Posterior Root:** - The neurosomas of sensory neurons associated with the posterior root (also called dorsal root ganglion neurons) are located within a swelling called the dorsal root ganglion (or spinal ganglion). - These ganglia are situated just outside the spinal cord, adjacent to the junction of the posterior (dorsal) root and the spinal cord. Each dorsal root ganglion contains the cell bodies of sensory neurons that transmit sensory information from peripheral receptors (e.g., skin, muscles, and organs) to the spinal cord. 2. **Neurosomas of the Anterior Root:** - The anterior root contains motor neurons that originate in the anterior (ventral) horn of the spinal cord. - Unlike the sensory neurons associated with the posterior root, the neurosomas of motor neurons in the anterior root are located within the gray matter of the spinal cord itself, specifically in the anterior horn of the gray matter. - These motor neurons give rise to axons that exit the spinal cord through the anterior root and then extend to target muscles and glands in the periphery. In summary, the neurosomas of sensory neurons are located in the dorsal root ganglion, which is just outside the spinal cord and associated with the posterior root. In contrast, the neurosomas of motor neurons are located within the gray matter of the spinal cord itself, specifically in the anterior horn, and are associated with the anterior root.

The neurosomas, also known as cell bodies or soma of neurons, within the spinal cord are not located in the posterior or anterior roots themselves. Instead, they are found in specific regions of the spinal cord. 1. **Neurosomas of the Posterior Root:** - The neurosomas of sensory neurons associated with the posterior root (also called dorsal root ganglion neurons) are located within a swelling called the dorsal root ganglion (or spinal ganglion). - These ganglia are situated just outside the spinal cord, adjacent to the junction of the posterior (dorsal) root and the spinal cord. Each dorsal root ganglion contains the cell bodies of sensory neurons that transmit sensory information from peripheral receptors (e.g., skin, muscles, and organs) to the spinal cord. 2. **Neurosomas of the Anterior Root:** - The anterior root contains motor neurons that originate in the anterior (ventral) horn of the spinal cord. - Unlike the sensory neurons associated with the posterior root, the neurosomas of motor neurons in the anterior root are located within the gray matter of the spinal cord itself, specifically in the anterior horn of the gray matter. - These motor neurons give rise to axons that exit the spinal cord through the anterior root and then extend to target muscles and glands in the periphery. In summary, the neurosomas of sensory neurons are located in the dorsal root ganglion, which is just outside the spinal cord and associated with the posterior root. In contrast, the neurosomas of motor neurons are located within the gray matter of the spinal cord itself, specifically in the anterior horn, and are associated with the anterior root.