Disc degeneration, due to the natural wear and tear of aging, is the most common cause of neural foraminal narrowing. Narrowing of the foramen may also be due to rheumatoid arthritis, osteoarthritis, chronic meningitis or tumors in the spinal column. Less often, the condition is congenital, or present at birth.
in human nervous system: Reflex actions. The anatomical pathway of a reflex is called the reflex arc. It consists of an afferent (or sensory) nerve, usually one or more interneurons within the central nervous system, and an efferent (motor, secretory, or secreto-motor) nerve. Read More.
noun. The nerve pathway involved in a reflex action, including at its simplest a sensory nerve and a motor nerve with a synapse between. Example sentences. 1  The changes in the blood vessel and local hemodynamics could be mediated via a reflex arc, consisting of somatic afferent and autonomic efferent components.2  These relaxations are vagally mediated, but the reflex arc that produces them can be affected by stimulation of other receptors.xample sentences. 1  The changes in the blood vessel and local hemodynamics could be mediated via a reflex arc, consisting of somatic afferent and autonomic efferent components.