Parasympathetic and sympathetic innervation

Parasympathetic fibers innervating heart

Arise from neurons in medulla oblongata of brain

cardioacceleratory center of medulla

sends signals through sympathetic trunk to increase both rate and force
Stimulates SA and AV nodes, heart muscle, and coronary arteries

Cardionhibitory center

Affects parasympathetic dorsal vagus nucleus; also in medulla

sympathetic nervous system

Accelerates heart rate, constricts blood vessels, raises blood pressure

parasympathetic nervous system

decreases heart rate