peripheral nervous system

The peripheral nervous system (PNS) encompasses all neural tissue outside the brain and spinal cord. It includes cranial nerves (12 pairs), spinal nerves (31 pairs), ganglia, and sensory receptors, and is divided into somatic and autonomic divisions.

The central nervous system (CNS) consists of the brain and spinal cord, which process and integrate information. The PNS connects the CNS to the rest of the body, transmitting sensory signals inward (afferent) and motor commands outward (efferent).

Unlike CNS neurons, peripheral nerves have significant regenerative capacity. Schwann cells in the PNS create a regenerative environment, and severed axons can regrow along the preserved myelin sheaths at approximately 1-3 mm per day, enabling partial or complete functional recovery.