Final answer:
Spinal nerves are classified as mixed nerves because they contain both sensory and motor fibers, enabling them to transmit information between the spinal cord and the body.
Step-by-step explanation:
Spinal nerves are mixed nerves, which means they contain both sensory (afferent) and motor (efferent) fibers. The sensory axons enter the spinal cord through the dorsal nerve root, and the motor fibers, both somatic and autonomic, emerge through the ventral nerve root. The dorsal root ganglion for each spinal nerve is an enlargement where the cell bodies of sensory neurons are located. These spinal nerves are essential for transmitting sensory and motor information between the spinal cord and the rest of the body, enabling a variety of bodily functions, including voluntary movements as part of the somatic nervous system and involuntary actions as part of the autonomic nervous system.