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Sep 21 2010, 8:21 PM EDT (current) AndyC 167 words added
Sep 21 2010, 8:17 PM EDT AndyC

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Cardiac plexus

  • Receives the superior, middle, and inferior cervical and thoracic cardiac nerves from the sympathetic trunks and vagus nerves.
  • Is divisible into the superficial cardiac plexus , which lies beneath the arch of the aorta in front of the pulmonary artery, and the deep cardiac plexus, which lies posterior to the arch of the aorta in front of the bifurcation of the trachea.
  • Richly innervates the conducting system of the heart: the right sympathetic and parasympathetic branches terminate chiefly in the region of the SA node, and the left branches end chiefly in the region of the AV node. The cardiac muscle fibers are devoid of motor endings and are activated by the conducting system.
  • Supplies the heart with sympathetic fibers, which increase the heart rate and the force of the heartbeat and cause dilation of the coronary arteries, and parasympathetic fibers, which decrease the heart rate and constrict the coronary arteries.


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