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.
Describe Monosynaptic reflex: When a reflex arc consists of only two neurons in an animal (one sensory neuron, and one motor neuron), it is defined as monosynaptic.Monosynaptic refers to the presence of a single chemical synapse.n polysynaptic reflex pathways, one or more interneurons connect afferent (sensory) and efferent (motor) signals. All but the most simple reflexes are polysynaptic, allowing processing or inhibition of polysynaptic reflexes within the spinal cord.