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Peripheral tissue at the outer end of an efferent neural path (one leading away from the central nervous system).

An effector acts in special ways in response to a nerve impulse. In humans, effectors may either be muscles, which contract in response to neural stimuli, or glands, which produce secretions. The muscles are generally divided into two groupings: somatic effectors, which are the body's striated muscles (such as those found in the arm and back), and autonomic effectors, which are smooth muscles (such as the iris of the eye).

Both types of effectors are linked to the gray matter of the spinal cord, but each system originates in a different portion of it. The somatic effectors, which are responsible for powerful motor movements, are linked to the ventral horn cell, a large