Dorsal root ganglion contains ?
**Core Concept**
The dorsal root ganglion (DRG) is a collection of nerve cell bodies that are located outside the central nervous system, specifically within the posterior root of spinal nerves. It is a critical structure for the transmission of sensory information from the periphery to the central nervous system.
**Why the Correct Answer is Right**
The DRG contains the cell bodies of sensory neurons, which are responsible for transmitting sensory information such as pain, temperature, touch, and proprioception from the sensory receptors in the skin and deeper tissues to the spinal cord. The cell bodies of these sensory neurons are located in the DRG, and their axons transmit the sensory signals to the spinal cord. The DRG is also the site where the myelination of the sensory axons occurs.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because the DRG does not contain the cell bodies of motor neurons, which are located in the ventral horn of the spinal cord.
**Option B:** This option is incorrect because the DRG does not contain the cell bodies of autonomic preganglionic neurons, which are located in the intermediolateral cell column of the spinal cord.
**Option C:** This option is incorrect because the DRG does not contain the cell bodies of interneurons, which are located within the spinal cord itself.
**Clinical Pearl / High-Yield Fact**
The DRG is an important structure for the diagnosis of certain neurological conditions, such as peripheral neuropathies, where the damage to the sensory axons can lead to pain, numbness, and tingling in the affected limbs.
**Correct Answer: C. Cell bodies of sensory neurons.**