What are the two main types of nerves that supply the heart?

The heart receives autonomic innervation from two systems: parasympathetic fibers (from vagus nerves) that slow heart rate, and sympathetic fibers (from thoracic spinal segments) that increase heart rate.

What is the function of parasympathetic nerve supply to the heart?

Parasympathetic fibers from the vagus nerves are cardioinhibitory. They slow heart rate and constrict coronary vessels.

What is the function of sympathetic nerve supply to the heart?

Sympathetic fibers from the upper thoracic spinal segments are cardioacceleratory. They increase heart rate and dilate coronary arteries.

What are the cardiac plexuses and where are they located?

The heart's autonomic nerves form two plexuses: the superficial cardiac plexus below the aortic arch, and the deep cardiac plexus in front of the tracheal bifurcation behind the aortic arch.

How does heart pain travel to the brain?

Pain from myocardial ischemia travels through sympathetic nerves to spinal segments T1-T5 via white rami communicantes. Sensory neurons are located in the dorsal root ganglia of these spinal nerves.

Where is heart pain typically felt (referred pain)?

Heart pain is typically referred to the pectoral region and medial arm/forearm. It may also radiate to the neck and mandible due to sympathetic connections.

What structures does the superficial cardiac plexus supply?

The superficial cardiac plexus distributes to the right coronary artery, left anterior pulmonary plexus, and deep cardiac plexus.

What structures does the deep cardiac plexus supply?

The deep cardiac plexus distributes to coronary arteries, pulmonary plexuses, and both atria.

Heart Nerve Supply – Sympathetic vs Parasympathetic

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