Where does the lesser petrosal nerve arise

Structure. After arising in the tympanic plexus, the lesser petrosal nerve passes forward and then through the hiatus for lesser petrosal nerve on the anterior surface of the petrous part of the temporal bone into the middle cranial fossa.

What makes up petrosal nerve?

The greater (superficial) petrosal nerve originates at the geniculate ganglion, where the nervus intermedius and facial nerve join. It contains mainly preganglionic parasympathetic fibers and some sensory taste afferent fibers from the soft palate.

How many Petrosal nerves are there?

Four to seven in number, the intercarotid nerves constitute, together with nerves issuing from the vagus and glossopharyngeal nerves, the intercarotid plexus. This plexus innervates the carotid bifurcation and the carotid body.

Where does the greater petrosal nerve exit the temporal bone?

The nerve proceeds anteromedially and exits the superior surface of the temporal bone through the hiatus of the greater petrosal nerve (facial hiatus/hiatus fallopii) and into the middle temporal fossa.

What is the lesser petrosal nerve?

Description. The lesser petrosal nerve (small superficial petrosal nerve) is the General visceral efferent (GVE) component of the glossopharyngeal nerve (CN IX), carrying parasympathetic fibers from the tympanic plexus to the parotid gland.

What is the tympanic nerve?

Medical Definition of tympanic nerve : a branch of the glossopharyngeal nerve arising from the petrosal ganglion and entering the middle ear where it takes part in forming the tympanic plexus. — called also Jacobson’s nerve.

Where do the preganglionic parasympathetic fibers of lesser petrosal nerve switch on postganglionic fibers?

The preganglionic parasympathetic fibers synapse with the cell bodies of the postganglionic parasympathetic fibers in the otic ganglion located on the V3 (medial side), around the origin of the nerve to the medial pterygoid (10).

Where is the chorda tympani located?

The chorda tympani is a nerve that arises from the mastoid segment of the facial nerve, carrying afferent special sensation from the anterior two-thirds of the tongue via the lingual nerve, as well as efferent parasympathetic secretomotor innervation to the submandibular and sublingual glands.

What is nervus intermedius?

The nervus intermedius is the sensory and parasympathetic division of the facial nerve. It contains visceral afferent fibers coming from the taste buds of the anterior two-thirds of the tongue and mucous membranes of the pharynx, nose, and palate. … Taste pathways of the facial nerve.

Is lesser petrosal branch of facial nerve?

The lesser petrosal nerve (Figure 26.3) is a continuation of the presynaptic fibers of the tympanic branch of the glossopharyngeal nerve with contributions from the nervus intermedius part of the facial nerve, and the auricular branch (Alderman’s or Arnold’s nerve) of the vagus nerve.

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What does the word Petrosal mean?

Definition of petrosal : of, relating to, or situated in the region of the petrous portion of the temporal bone or capsule of the inner ear.

What passes through the Vidian canal?

It transmits the nerve of pterygoid canal, (Vidian nerve), the artery of the pterygoid canal (Vidian artery), and the vein of the pterygoid canal (Vidian vein).

What does deep Petrosal innervate?

The deep petrosal nerve carries postganglionic sympathetic axons to the pterygopalatine ganglion, which pass through without synapsing. These axons innervate blood vessels and mucous glands of the head and neck.

What nerve supplies Stapedius?

The branches of the facial nerve: The nerve to stapedius innervates the stapedius muscle.

What is the foramen Rotundum?

The foramen rotundum is a circular hole in the sphenoid bone of the skull. It connects the middle cranial fossa and the pterygopalatine fossa.

What is Jacobson nerve?

Jacobson’s nerve is a tympanic branch of the glossopharyngeal nerve, arising from its inferior ganglion. It enters the middle ear cavity through the inferior tympanic canaliculus, runs in a canal on the cochlear promontory and provides the main sensory innervation to the mucosa of the mesotympanum and Eustachian tube.

Where is submandibular ganglion?

The submandibular ganglion is small and fusiform in shape. It is situated above the deep portion of the submandibular gland, on the hyoglossus muscle, near the posterior border of the mylohyoid muscle.

What is the geniculate ganglion?

The geniculate ganglion is a sensory ganglion of the facial nerve (CN VII). It contains the cell bodies of the fibers responsible for conducting taste sensation from the anterior two-thirds of the tongue.

Where does the tympanic nerve come from?

The tympanic nerve arises from the inferior ganglion of the glossopharyngeal nerve traversing through the tympanic canaliculus into the middle ear. On the promontory it coalesces with sympathetic fibres from the carotid chain forming the tympanic plexus.

How is tympanic plexus formed?

In the middle ear, the tympanic plexus is formed on the tympanic promontory by branches of Jacobson’s nerve (tympanic branch of the glossopharyngeal nerve) and caroticotympanic nerves originating from the internal carotid artery plexus.

What nucleus of Vestibulocochlear nerve is Cochlear?

The cochlear nuclear complex is located in the dorsolateral portion of the rostral medulla oblongata, lateral to the inferior cerebellar peduncle.

What is nervus intermedius neuralgia?

Nervus intermedius neuralgia is an extremely uncommon pain syndrome in which the pain is very similar to that of trigeminal neuralgia but in the distribution of n. intermedius. Generally it is presumed that its etiology is the cross compression of the nerve at its central-peripheral myelin junction.

What is Stapedius muscle?

Stapedius muscle is termed to be the smallest skeletal muscle in human body, which has a major role in otology. Stapedius muscle is one of the intratympanic muscles for the regulation of sound.

What is the ciliary ganglion?

Ciliary ganglion is a peripheral parasympathetic ganglion. It is situated near the apex of orbit between the optic nerve and lateral rectus muscle. It is related medially to the ophthalmic artery and laterally to the lateral rectus muscle.

What is the origin of the chorda tympani nerve?

The chorda tympani nerve arises from the facial nerve a few millimeters above the stylomastoid foramen. It is directed superior and anterior, and perforates the tympanic cavity. It enters the posterior canaliculus and then descends near the spine of the sphenoid bone.

What nerve supplies taste to tongue?

The three nerves associated with taste are the facial nerve (cranial nerve VII), which provides fibers to the anterior two-thirds of the tongue; the glossopharyngeal nerve (cranial nerve IX), which provides fibers to the posterior third of the tongue; and the vagus nerve (cranial nerve X), which provides fibers to the …

Why is tympani called chorda?

Structure and Location. After splitting off from the intracranial branch of the facial nerve, the chorda tympani enters the ear. Its association with the ear is what gives the chorda tympani its name.

Where is foramen Spinosum?

The foramen spinosum is located in the skull base and transmits the middle meningeal artery and meningeal branch of the mandibular nerve [1].

Why is it called the temporal bone?

Etymology. Its exact etymology is unknown. It is thought to be from the Old French temporal meaning “earthly,” which is directly from the Latin tempus meaning “time, proper time or season.” Temporal bones are situated on the sides of the skull, where grey hairs usually appear early on.

Why is Petrous used to describe the temporal bone?

Why is this term used to describe the petrous part of the temporal bone? It houses sensory structures of the inner ear that provide information about hearing and balance. What structures are found deep within the petrous part of the temporal bone?