Final answer:
The heart is regulated by the cardiovascular centers in the medulla oblongata, balancing sympathetic and parasympathetic influences primarily through the cardioaccelerator nerves and the vagus nerve.
Step-by-step explanation:
Neural Regulation of the Heart
The heart receives its neural control from the cardiovascular centers located in the medulla oblongata. These centers manage the balance of sympathetic and parasympathetic nervous system input to the heart. The sympathetic stimulation, conducted through the cardioaccelerator nerves, increases heart activity, while parasympathetic stimulation, particularly from the vagus nerve, reduces heart rate. The solitary nucleus and the dorsal motor nucleus of the vagus nerve are key components of this regulatory system, responding to various sensory inputs and providing appropriate output to either stimulate or relax heart function.
During periods of rest, there is slight stimulation from both the sympathetic and parasympathetic systems, contributing to what is known as autonomic tone. However, the vagal tone generally predominates in a resting state. When there are changes in the cardiovascular system's homeostasis, such as fluctuations in blood pressure, the medulla coordinates a response. Increased sympathetic activity can also occur in response to stress, where the cardiac accelerator nerves are stimulated.