The spinal cord, a critical component of the central nervous system, extends from the base of the brainstem to the lumbar region of the vertebral column. It is essential for maintaining physical stability and facilitating communication between the brain and peripheral parts of the body.
The spinal cord consists of three primary types of nerve cells: sensory neurons, motor neurons, and interneurons.
A notable function of the spinal cord is its ability to coordinate reflex actions independently of the brain. Reflex arcs are neural circuits that activate directly in response to sensory inputs to produce immediate reactions. For instance, upon touching a hot surface, sensory neurons quickly send a signal to the spinal cord. Interneurons immediately process this information and activate motor neurons, resulting in the rapid withdrawal of the hand. This reflex action occurs to protect the body from harm and highlights the spinal cord's complex functionality and its critical role in the human body's operational hierarchy.