Parasympathetic ganglia
Encyclopedia
Parasympathetic ganglia are the autonomic ganglia of the parasympathetic nervous system
. Most are small terminal ganglia or intramural ganglia, so named because they lie near or within (respectively) the organs they innervate. The exceptions are the four paired parasympathetic ganglia of the head and neck.
Some ganglia also carry special sensory fibers (SVA
) for taste
sensation.
Parasympathetic nervous system
The parasympathetic nervous system is one of the two main divisions of the autonomic nervous system . The ANS is responsible for regulation of internal organs and glands, which occurs unconsciously...
. Most are small terminal ganglia or intramural ganglia, so named because they lie near or within (respectively) the organs they innervate. The exceptions are the four paired parasympathetic ganglia of the head and neck.
Parasympathetic ganglia of the head and neck
These paired ganglia supply all parasympathetic innervation to the head and neck.- ciliary ganglionCiliary ganglionThe ciliary ganglion is a parasympathetic ganglion located in the posterior orbit. It measures 1–2 millimeters in diameter and contains approximately 2,500 neurons. Preganglionic axons from the Edinger-Westphal nucleus travel along the oculomotor nerve and form synapses with these cells...
(spincter pupillae, ciliary muscleCiliary muscleThe ciliary muscle is a ring of striated smooth muscle in the eye's middle layer that controls accommodation for viewing objects at varying distances and regulates the flow of aqueous humour into Schlemm's canal. It changes the shape of the lens within the eye not the size of the pupil which is...
) - pterygopalatine ganglionPterygopalatine ganglionThe pterygopalatine ganglion is a parasympathetic ganglion found in the pterygopalatine fossa. It is one of four parasympathetic ganglia of the head and neck....
(lacrimal glandLacrimal glandThe lacrimal glands are paired almond-shaped glands, one for each eye, that secrete the aqueous layer of the tear film. They are situated in the upper, outer portion of each orbit, in the lacrimal fossa of the orbit formed by the frontal bone. Inflammation of the lacrimal glands is called...
, glands of nasal cavityNasal cavityThe nasal cavity is a large air filled space above and behind the nose in the middle of the face.- Function :The nasal cavity conditions the air to be received by the other areas of the respiratory tract...
) - submandibular ganglionSubmandibular ganglionThe submandibular ganglion is part of the human autonomic nervous system. It is one of four parasympathetic ganglia of the head and neck...
(submandibularSubmandibular glandThe paired submandibular glands are salivary glands located beneath the floor of the mouth. In humans, they account for 70% of the salivary volume and weigh about 15 grams. Unstimulated in humans, the percentage contribution to whole saliva; ~25% Parotid, Submandibular and Sublingual ~ 67% and...
and sublingualSublingual glandThe sublingual glands are salivary glands in the mouth.They lie anterior to the submandibular gland under the tongue, beneath the mucous membrane of the floor of the mouth.They are drained by 8-20 excretory ducts called the ducts of Rivinus....
glands) - otic ganglionOtic ganglionThe otic ganglion is a small, oval shaped, flattened parasympathetic ganglion of a reddish-gray color, located immediately below the foramen ovale in the infratemporal fossa. It gives innervation to the parotid gland for salivation....
(parotid glandParotid glandThe paired parotid glands are the largest of the salivary glands. They are each found wrapped around the mandibular ramus, and secrete saliva through Stensen's ducts into the oral cavity, to facilitate mastication and swallowing and to begin the digestion of starches.-Location:The parotid glands...
)
Roots
Each has three roots entering the ganglion and a variable number of exiting branches.- The motor root carries presynaptic parasympathetic nerve fibers (GVE) that terminate in the ganglion by synapsing the postsynaptic fibers traveling to target organs.
- The sympathetic root carries postsynaptic sympathetic fibers (GVE) that traverse the ganglion without synapsing.
- The sensory root carries general sensory fibers (GSAGeneral somatic afferent fibersThe general somatic afferent fibers , afferent fibers, arise from cells in the spinal ganglia and are found in all the spinal nerves, except occasionally the first cervical, and conduct impulses of pain, touch and temperature from the surface of the body through the posterior roots to the spinal...
) that also do not synapse in the ganglion.
Some ganglia also carry special sensory fibers (SVA
Special visceral afferent
' refers to afferent nerves that develop in association with the gastrointestinal tract. They carry the special senses of smell and taste . The cranial nerves containing SVA fibers are the olfactory nerve , the facial nerve , the glossopharyngeal nerve and the vagus nerve...
) for taste
Taste
Taste is one of the traditional five senses. It refers to the ability to detect the flavor of substances such as food, certain minerals, and poisons, etc....
sensation.
Nerves supplying parasympathetic fibers
- oculomotor nerveOculomotor nerveThe oculomotor nerve is the 3rd of 12 paired cranial nerves. It enters the orbit via the superior orbital fissure and controls most of the eye's movements, including constriction of the pupil and maintaining an open eyelid by innervating the Levator palpebrae superiors muscle. The optic nerve is...
(ciliary ganglionCiliary ganglionThe ciliary ganglion is a parasympathetic ganglion located in the posterior orbit. It measures 1–2 millimeters in diameter and contains approximately 2,500 neurons. Preganglionic axons from the Edinger-Westphal nucleus travel along the oculomotor nerve and form synapses with these cells...
) - facial nerveFacial nerveThe facial nerve is the seventh of twelve paired cranial nerves. It emerges from the brainstem between the pons and the medulla, and controls the muscles of facial expression, and functions in the conveyance of taste sensations from the anterior two-thirds of the tongue and oral cavity...
(pterygopalatine ganglionPterygopalatine ganglionThe pterygopalatine ganglion is a parasympathetic ganglion found in the pterygopalatine fossa. It is one of four parasympathetic ganglia of the head and neck....
, submandibular ganglionSubmandibular ganglionThe submandibular ganglion is part of the human autonomic nervous system. It is one of four parasympathetic ganglia of the head and neck...
) - glossopharyngeal nerveGlossopharyngeal nerveThe glossopharyngeal nerve is the ninth of twelve pairs of cranial nerves . It exits the brainstem out from the sides of the upper medulla, just rostral to the vagus nerve...
(otic ganglionOtic ganglionThe otic ganglion is a small, oval shaped, flattened parasympathetic ganglion of a reddish-gray color, located immediately below the foramen ovale in the infratemporal fossa. It gives innervation to the parotid gland for salivation....
) - vagus nerveVagus nerveThe vagus nerve , also called pneumogastric nerve or cranial nerve X, is the tenth of twelve paired cranial nerves...
(no named ganglion) - Pelvic splanchnic nervesPelvic splanchnic nervesPelvic splanchnic nerves or nervi erigentes are splanchnic nerves that arise from sacral spinal nerves S2, S3, S4 to provide parasympathetic innervation to the hindgut.-Structure:...
(no named ganglion)
External links
- The Autonomic Nervous System from the University of Arizona
- Diagrams
- "Terminal ganglion - Auerbach's plexus - plastic section"