Some of the physiologic effects of neuraxial anesthesia are the result of blockade of sympathetic nerves, compensatory reflexes, and unopposed parasympathetic tone. The magnitude of various physiologic effects depends on the extent and speed of onset of block, and patient factors. For further information refer to UpToDate content on neuraxial anesthesia. The anatomy of the autonomic nervous system is variable among patients and among anatomy sources.
Modified from: Cohen BJ, Hull KL. Memmler’s Structure and Function of the Human Body, 11th ed, Wolters Kluwer, Philadelphia 2016.