Internal carotid plexus | |
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Details | |
Identifiers | |
Latin | plexus caroticus internus |
TA98 | A14.3.03.004 |
TA2 | 6645 |
FMA | 67533 |
Anatomical terms of neuroanatomy |
The internal carotid plexus is a nerve plexus situated upon the lateral side of the internal carotid artery. It is composed of post-ganglionic sympathetic fibres which have synapsed at (i.e. have their nerve cell bodies at) the superior cervical ganglion. The plexus gives rise to the deep petrosal nerve. [1]
Postganglionic sympathetic fibres ascend from the superior cervical ganglion, along the walls of the internal carotid artery, to enter the internal carotid plexus. These fibres are then distributed to deep structures, including the superior tarsal muscle and pupillary dilator muscle. [2] It includes fibres destined for the pupillary dilator muscle as part of a neural circuit regulating pupillary dilatation component of the pupillary reflex. [3] Some fibres of the plexus converge to form the deep petrosal nerve. [4]
The internal carotid plexus communicates with the trigeminal ganglion, the abducent nerve, and the pterygopalatine ganglion (also named sphenopalatine); it distributes filaments to the wall of the internal carotid artery, and also communicates with the tympanic branch of the glossopharyngeal nerve.[ citation needed ]
The plexus there occasionally presents a small gangliform swelling - the carotid ganglion - on the under surface of the artery.[ citation needed ]
Articles related to anatomy include:
The oculomotor nerve, also known as the third cranial nerve, cranial nerve III, or simply CN III, is a cranial nerve that enters the orbit through the superior orbital fissure and innervates extraocular muscles that enable most movements of the eye and that raise the eyelid. The nerve also contains fibers that innervate the intrinsic eye muscles that enable pupillary constriction and accommodation. The oculomotor nerve is derived from the basal plate of the embryonic midbrain. Cranial nerves IV and VI also participate in control of eye movement.
The internal carotid artery is an artery in the neck which supplies the anterior circulation of the brain.
The otic ganglion is a small parasympathetic ganglion located immediately below the foramen ovale in the infratemporal fossa and on the medial surface of the mandibular nerve. It is functionally associated with the glossopharyngeal nerve and innervates the parotid gland for salivation.
The pterygopalatine ganglion is a parasympathetic ganglion in the pterygopalatine fossa. It is one of four parasympathetic ganglia of the head and neck,.
The ciliary ganglion is a parasympathetic ganglion located just behind the eye in the posterior orbit. It is 1–2 mm in diameter and in humans contains approximately 2,500 neurons. The ganglion contains postganglionic parasympathetic neurons. These neurons supply the pupillary sphincter muscle, which constricts the pupil, and the ciliary muscle which contracts to make the lens more convex. Both of these muscles are involuntary since they are controlled by the parasympathetic division of the autonomic nervous system.
The iris dilator muscle, is a smooth muscle of the eye, running radially in the iris and therefore fit as a dilator. The pupillary dilator consists of a spokelike arrangement of modified contractile cells called myoepithelial cells. These cells are stimulated by the sympathetic nervous system. When stimulated, the cells contract, widening the pupil and allowing more light to enter the eye.
The greater petrosal nerve is a nerve of the head mainly containing pre-ganglionic parasympathetic fibres which ultimately synapse in the pterygopalatine ganglion. It branches from the facial nerve and is derived from the parasympathetic part of the nervus intermedius component of CN VII, with its cell bodies located in the superior salivary nucleus. In the connective tissue substance of the foramen lacerum, the greater petrosal nerve unites with the (sympathetic) deep petrosal nerve to form the nerve of the pterygoid canal which proceeds to the pterygopalatine ganglion.
The stylopharyngeus muscle is a muscle in the head. It originates from the temporal styloid process. Some of its fibres insert onto the thyroid cartilage, while others end by intermingling with proximal structures. It is innervated by the glossopharyngeal nerve. It acts to elevate the larynx and pharynx, and dilate the pharynx, thus facilitating swallowing.
The trigeminal ganglion is the sensory ganglion of each trigeminal nerve. The trigeminal ganglion is located within the trigeminal cave, a cavity formed by dura mater.
The superior cervical ganglion (SCG) is the upper-most and largest of the cervical sympathetic ganglia of the sympathetic trunk. It probably formed by the union of four sympathetic ganglia of the cervical spinal nerves C1–C4. It is the only ganglion of the sympathetic nervous system that innervates the head and neck. The SCG innervates numerous structures of the head and neck.
The sympathetic trunks are a paired bundle of nerve fibers that run from the base of the skull to the coccyx. They are a major component of the sympathetic nervous system.
The short ciliary nerves are nerves of the orbit around the eye. They are branches of the ciliary ganglion. They supply parasympathetic and sympathetic nerve fibers to the ciliary muscle, iris, and cornea. Damage to the short ciliary nerve may result in loss of the pupillary light reflex, or mydriasis.
The deep petrosal nerve is a post-ganglionic branch of the (sympathetic) internal carotid (nervous) plexus that enters the cranial cavity through the carotid canal, then passes perpendicular to the carotid canal in the cartilaginous substance which fills the foramen lacerum to unite with the (parasympathetic) greater petrosal nerve to form the nerve of pterygoid canal.
The nerve of the pterygoid canal is formed by the union of the (parasympathetic) greater petrosal nerve and (sympathetic) deep petrosal nerve within the cartilaginous substance filling the foramen lacerum. From the foramen lacerum, the nerve of the pterygoid canal passes through the pterygoid canal to reach the pterygopalatine fossa, ending at the pterygopalatine ganglion.
The superior cardiac nerve arises by two or more branches from the superior cervical ganglion, and occasionally receives a filament from the trunk between the first and second cervical ganglia. It runs down the neck behind the common carotid artery, and in front of the Longus colli muscle; and crosses in front of the inferior thyroid artery, and recurrent nerve. The course of the nerves on the two sides then differs.
The ciliospinal center is a cluster of pre-ganglionic sympathetic neuron cell bodies located in the intermediolateral cell column of the spinal cord at the (C8) T1-T2 spinal levels.
The following outline is provided as an overview of and topical guide to human anatomy:
The ciliary ganglion is a parasympathetic ganglion located just behind the eye in the posterior orbit. Three types of axons enter the ciliary ganglion but only the preganglionic parasympathetic axons synapse there. The entering axons are arranged into three roots of the ciliary ganglion, which join enter the posterior surface of the ganglion.
This article incorporates text in the public domain from page 977 of the 20th edition of Gray's Anatomy (1918)