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Organization of the Autonomic System

  • Nerves also contain neurons of the visceral or image descriptionautonomic nervous system (ANS), which connect the central nervous system (CNS) to the viscera.
An image showing the organization of the ANS (autonomic nervous system), how action potentials move through ANS, from or to the CNS
An image showing the organization of the ANS (autonomic nervous system), how action potentials move through ANS, from or to the CNS, the (CNS, ANS, Organs [viscera] ) are labeled
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  • The viscera are the soft organs found in the respiratory, circulatory, endocrine, digestive, urinary, and reproductive systems. Examples of viscera include the heart, glands, and smooth muscles.

An image showing a table contains the organs which are regulated by the ANS and the response of those organs

 

  • The autonomic neural network allows the brain to involuntarily (subconsciously or unconsciously) monitor changes in the internal environment and control the activities of the viscera.
  • Activity of the ANS is regulated by brain control centers in the hypothalamus and brainstem.
  • Input is sent to the ANS control centers from higher levels of the brain (cerebral cortex and limbic system) and sensory receptors embedded in the viscera. Autonomic sensory neurons conduct signals from the visceral receptors to the CNS.

An image showing the stimulation in the viscera generating action potential which moves through sensory neuron (ANS) to reach the higher levels (CNS)

  • Using the sensory input, the ANS control centers develop appropriate responses (reflexes), which are then relayed to autonomic motor neurons.

An image showing the action potential moving from the high centers (CNS) stimulating autonomic neuron to control ANS response

  • Autonomic motor neurons carry signals out of the CNS to the heat, glands and smooth muscle. Each pathway to an effector location consists of two neurons.

An image showing the autonomic motor neuron carries the signal from the higher level (CNS) to the viscera

  • Functionally and anatomy, the motor divided into the sympathetic and parasympathetic nervous systems.
  • The sympathetic N.S. promotes activities that help the body cope with stress (fight or flight responses).

An image showing the action potential moves through SNS (sympathetic nervous system) neuron from the CNS to reach viscera (Feed or breed)

  • In contrast, the parasympathetic N.S. promotes activities that support the body while at rest (feed and breed).

An image showing the action potential moves through PNS (parasympathetic nervous system) neuron from the CNS to reach viscera (Feed or breed)