Spinal Cord Essay

The spinal cord, part of the central nervous system (CNS), is a continuous cylinder of nerve fibers with thirty-one pairs of spinal nerves branching out into designated regions of the body. The inner region of the spinal cord consists of gray matter. Within the gray matter, afferent neurons terminate from sensory receptors in the body and efferent neurons originate. The efferent neurons travel away from the spinal cord to form synapses with skeletal muscles. These neurons use the same spinal nerves, however afferent axons group together in dorsal roots and efferent axons group together in ventral roots. The outer region of the spinal cord consists of white matter. Within the white matter, ascending tracts carry information from the spinal cord to the brain and descending tracts carry information from the brain to the spinal cord (Standfield, 2011). Dermatomes are areas of the skin supplied by each root by sensory axons and myotomes are collections of muscle fibers supplied by each root by motor axons (Maynard Jr et al, 1997).
A reflex is the body’s automatic response to a stimulus. A reflex arc starts when a sensory receptor is stimulated. Afferent neurons carry the information from the receptor to the CNS to be integrated. The CNS sends signals to efferent neurons, which then relay to an effector organ thereby producing a response. …show more content…
Neurological level refers to segments of the spinal cord with normal sensory and motor function on the right and left sides of the body. Tetraplegia is the impairment or loss of motor and sensory function in arms, trunk, legs, and pelvic organs due to damage of the cervical segments in the spinal cord. Paraplegia is the impairment or loss of motor and sensory function in either or all of the legs, pelvic organs, and trunk due to damage of the thoracic, lumbar, or sacral segments in the spinal cord (Maynard Jr et al,