Nervous regulation of the heart

Under normal physiological conditions, the activity of the heart at each point corresponds to changes in the environment surrounding the body, and the vibrations of its internal environment. This correspondence of the heart conditions of existence of the body due to the reflex regulation of the activity of the heart. Nerve impulses that regulate the heart, sent to him from the central nervous system on two pairs of centrifugal nerves: the sympathetic and the vagus.

The sympathetic nerves of the heart come from neurons in the lateral horn of the spinal cord from the 1st to the 5th thoracic segment and reach in mammals to lower cervical node and up to 1st thoracic (stellate) node sympathetic chain. These nodes preduzlovye fibers are contacted with the bodies disposed therein neurons from which fibers are sent after the node to the muscle fibers of the heart.

The nuclei of the vagus nerves are located in the medulla oblongata. Of these, the fibers of these nerves reach cardiac ganglia. Most of the fibers right vagus nerve reaches sinusoatrialnogo node and smaller – to the atrioventricular node. Conversely, most of the left vagus nerve fibers reaches the atrioventricular node, and smaller – to sinusoatrialnogo node.
At the approach to the heart of sympathetic fibers are attached to the fibers of the vagus nerve, and therefore a significant part of one cardiac nerve plexus contains those and other fibers.


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Nervous regulation of the heart