CN X (vagus) does indeed have partial control over heart rate, but as a
PARAsympathetic efferent. It innervates mostly the atria. Postganglio-
nic sympathetic efferents exist throughout both atria and ventricles.
Pretty much any book on cardiac physiology could act as a reference, my
favorite is Guyton 8th ed. _Textbook of Medical Physiology_
J. Harper, MS, RN, CCRN
Doctoral Student, Neuroscience/Nursing
UC San Francisco
jharper at itsa.ucsf.edu
