92 Neuroanatomy: Draw It to Know It
Know-It Points
Autonomic Fiber Arrangements
■ Th e parasympathetic nervous system originates
within the cranial nerve nuclei and the sacral
intermediolateral cell column from S2 to S4.
■ Th e sympathetic nervous system originates within the
thoracolumbar intermediolateral cell column from
T1 to L2.
■ Parasympathetic ganglia lie close to (or within) their
target organ.
■ Sympathetic ganglia lie far from their target organ.
■ Preganglionic parasympathetic and sympathetic
neurons release acetylcholine.
■ Postganglionic parasympathetic fi bers release
acetylcholine.
■ Postganglionic sympathetic fi bers release
norepinephrine (except for those fi bers to the sweat
glands and adrenal gland, which release acetylcholine
and epinephrine, respectively).Parasympathetic Nervous System
■ Th e Edinger-Westphal nucleus of cranial nerve 3
innervates the ciliary ganglion.
■ Th e superior salivatory nucleus of cranial nerve 7
innervates both the pterygopalatine and
submandibular ganglia.
■ Th e inferior salivatory nucleus of cranial nerve 9
innervates the otic ganglion.
■ Th e dorsal motor nucleus of the vagus nerve of
cranial nerve 10 innervates the ganglia of numerous
pharyngeal and thoracoabdominal glands and
organs.
■ Th e nucleus ambiguus of cranial nerves 9 and 10
innervates ganglia related to the carotid body and
carotid sinus and the cardiac ganglion.
■ Sacral nuclei of the intermediolateral cell column
(S2–S4) project to abdomino-pelvic ganglia.Sympathetic Nervous System
■ Th e paravertebral chain lies just lateral to the
vertebral column.
■ Superior cervical ganglion fi bers ascend the carotid
artery to innervate the head and neck.
■ Loss of sympathetic tone to the face results in
Horner’s syndrome: ptosis, miosis, and anhidrosis.
■ Sympathetic splanchnic nerves innervate the four
prevertebral ganglia.
■ Certain preganglionic sympathetic fi bers synapse
directly in adrenal medullary chromaffi n c e l l s.