Download Anatomy of the Parasympathetic (Craniosacral) Division

Anatomy of the Parasympathetic
(Craniosacral) Division
The nerve fibers that constitute the parasympathetic division originate
at the two anatomical ends of the central nervous system. The cranial
nerves, CN III, CN VII, CN IX and CN X and the sacral spinal nerves S2,
S3 and S4 carry the presynaptic (or, pre-ganglionic) parasympathetic
outflow. The presynaptic neurons of the sacral part of the Craniosacral
division lie in the lateral horns of the spinal cord at the appropriate
level. These neurons extend into the body’s internal organs only and
synapse
at
the terminal (that
lie
close
to
the
organ)
or intramural (within the target organ) ganglia. The exceptions are
the four-paired parasympathetic ganglia of the head and neck. Of the
four
cranial
nerves
mentioned
above,
CNIII
supplies
the ciliaryganglion; CNVII supplies
the pterygopalatine and submandibular
ganglia;
and CNIX supplies theotic ganglion. The Vagus nerve (CNX), as
you have learned before, gets its name from its “wandering” nature. It
does wander in the thoracic and abdominopelvic cavities in your body to
synapse on postsynaptic (or postganglionic) neurons that innervate the
heart, bronchi, stomach, liver and the intestines. There are no named
ganglia for these organs.