National Nursing Review : Nursing Study Resources & Health Tips

The heart muscle does not require external stimulation to contract, but the autonomic nervous system exerts a considerable influence on the latter.
The control centers of the cardiac autonomic nervous system located in the medulla oblongata: the cardio accelerator center plans neuronal extensions even neurons segments T1 -> T5 spinal cord, which synapse with postganglionic neurons of cervical lymph and upper chest, from where they are nerve fibers synapse with sinus and atrioventricular nodes.
The cardiovascular center inhibitor, it has the nerve fibers which leave the medulla oblongata to the heart via the nerve X.

The phenomena of electrical stimulation:
The cells are pacemakers in the sinus node, the atrioventricular node and atrioventricular bundle (bundle of His). The sinus node is located in the wall of the right atrium. It is the primary pacemaker center: typically, the sinus node depolarizes spontaneously 70 times per minute, and mark the pace of all contractile cells. (more…)