Inadequate frameworks for understanding bodily homeostasis.

Separate nervous systems, somatic and autonomic, were proposed to regulate the portion of the individual's life that is concerned with the external environment and the portion that is concerned with internal homeostasis. Regulation of the autonomic system by the CNS was assigned to the limbic system. Brainstem circuitry, between limbic and autonomic systems, was assigned to the supposedly nonspecific reticular formation. In fact, daily survival depends on integrated control of behavior and internal physiology. In mammals only the brain has the inbuilt programming for patterned co-ordination of these activities. The terms autonomic nervous system, limbic system and reticular formation are at odds with this patterned co-ordination. They should be abandoned and replaced with the term visceral neurons (afferent and efferent) and with reference to relevant specific-neural circuitry in the brain.