Craniosacral part of autonomic division

Craniosacral part of autonomic division: The craniosacral component of the autonomic nervous system corresponds to the parasympathetic division. It is characterized by cholinergic neurons, which release acetylcholine (Ach) as their neurotransmitter. Parasympathetic preganglionic fibres originate in the cranial and sacral regions, extending through various ganglia to innervate target organs.

In the cranial region, preganglionic fibres arise from specific nuclei in the midbrain:

• Edinger-Westphal Nucleus: Fibres travel via the oculomotor nerve (cranial nerve III) to the ciliary ganglion.

• Superior Salivatory Nucleus: Fibres traverse the facial nerve (cranial nerve VII) to reach the pterygopalatine and submandibular ganglia.

• Inferior Salivatory Nucleus: Fibres run through the glossopharyngeal nerve (cranial nerve IX) to the otic ganglion.

• Dorsal Nucleus of the Vagus Nerve: Fibres exit through the vagus nerve (cranial nerve X), innervating thoracic and abdominal organs.

In the sacral region (spinal levels S2–S4), parasympathetic preganglionic fibres innervate pelvic organs, such as the colon, rectum, bladder, and reproductive structures. This craniosacral outflow provides essential autonomic control to visceral structures, emphasizing homeostasis and rest-and-digest functions.