Petrotympanic fissure

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Petrotympanic fissure
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Left temporal bone. Outer surface. (Petrotympanic fissure is labeled at left, fourth from top.)
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The right membrana tympani with the hammer and the chorda tympani, viewed from within, from behind, and from above. (Glaserian fissure labeled at center left.)
Details
Identifiers
Latin fissura petrotympanica
TA98 A02.1.06.074
TA2 717
FMA 55463
Anatomical terms of bone

The petrotympanic fissure (also known as the squamotympanic fissure or the glaserian fissure) is a fissure in the temporal bone [1] that runs from the temporomandibular joint to the tympanic cavity. [2]

Contents

The mandibular fossa is bounded, in front, by the articular tubercle; behind, by the tympanic part of the bone, which separates it from the external acoustic meatus; it is divided into two parts by a narrow slit, the petrotympanic fissure.

It opens just above and in front of the ring of bone into which the tympanic membrane is inserted; in this situation it is a mere slit about 2 mm. in length. It lodges the anterior process and anterior ligament of the malleus, and gives passage to the anterior tympanic branch of the internal maxillary artery.

Eponym

It is also known as the "Glaserian fissure", after Johann Glaser. [3]

Contents

The contents of the fissure include communications of cranial nerve VII to the infratemporal fossa. A branch of cranial nerve VII, the chorda tympani, runs through the fissure to join with the lingual nerve providing special sensory (taste) innervation to the tongue. Anterior tympanic artery and tympanic veins also pass through the structure. Petrotympanic fissure contains some of the fibers of the anterior ligament of malleus, which run on the base of skull and eventually attach onto the spine of sphenoid bone.

See also

Related Research Articles

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<span class="mw-page-title-main">Temporomandibular joint</span> Joints connecting the jawbone to the skull

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Articles related to anatomy include:

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<span class="mw-page-title-main">Middle meningeal artery</span> Artery supplying the meninges

The middle meningeal artery is typically the third branch of the first portion of the maxillary artery. After branching off the maxillary artery in the infratemporal fossa, it runs through the foramen spinosum to supply the dura mater and the calvaria. The middle meningeal artery is the largest of the three (paired) arteries that supply the meninges, the others being the anterior meningeal artery and the posterior meningeal artery.

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The auriculotemporal nerve is a sensory branch of the mandibular nerve (CN V3) that runs with the superficial temporal artery and vein, and provides sensory innervation to parts of the external ear, scalp, and temporomandibular joint. The nerve also conveys post-ganglionic parasympathetic fibres from the otic ganglion to the parotid gland.

<span class="mw-page-title-main">Chorda tympani</span> Nerve carrying taste sensations

Chorda tympani is a branch of the facial nerve that carries gustatory (taste) sensory innervation from the front of the tongue and parasympathetic (secretomotor) innervation to the submandibular and sublingual salivary glands.

<span class="mw-page-title-main">Tympanic cavity</span> Small cavity surrounding the bones of the middle ear

The tympanic cavity is a small cavity surrounding the bones of the middle ear. Within it sit the ossicles, three small bones that transmit vibrations used in the detection of sound.

<span class="mw-page-title-main">Internal auditory meatus</span> Canal within the temporal bone

The internal auditory meatus is a canal within the petrous part of the temporal bone of the skull between the posterior cranial fossa and the inner ear.

<span class="mw-page-title-main">Sphenomandibular ligament</span>

The sphenomandibular ligament is one of the three ligaments of the temporomandibular joint. It is situated medially to - and generally separate from - the articular capsule of the joint. Superiorly, it is attached to the spine of the sphenoid bone; inferiorly, it is attached to the lingula of mandible. The SML acts to limit inferior-ward movement of the mandible.

<span class="mw-page-title-main">Squamous part of temporal bone</span> Front and upper part of the sides of the skull base

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<span class="mw-page-title-main">Petrous part of the temporal bone</span> Feature at the base of the human skull

The petrous part of the temporal bone is pyramid-shaped and is wedged in at the base of the skull between the sphenoid and occipital bones. Directed medially, forward, and a little upward, it presents a base, an apex, three surfaces, and three angles, and houses in its interior, the components of the inner ear. The petrous portion is among the most basal elements of the skull and forms part of the endocranium. Petrous comes from the Latin word petrosus, meaning "stone-like, hard". It is one of the densest bones in the body. In other mammals, it is a separate bone, the petrosal bone.

<span class="mw-page-title-main">Middle cranial fossa</span>

The middle cranial fossa is formed by the sphenoid bones, and the temporal bones. It lodges the temporal lobes, and the pituitary gland. It is deeper than the anterior cranial fossa, is narrow medially and widens laterally to the sides of the skull. It is separated from the posterior cranial fossa by the clivus and the petrous crest.

<span class="mw-page-title-main">Anterior cranial fossa</span>

The anterior cranial fossa is a depression in the floor of the cranial base which houses the projecting frontal lobes of the brain. It is formed by the orbital plates of the frontal, the cribriform plate of the ethmoid, and the small wings and front part of the body of the sphenoid; it is limited behind by the posterior borders of the small wings of the sphenoid and by the anterior margin of the chiasmatic groove. The lesser wings of the sphenoid separate the anterior and middle fossae.

<span class="mw-page-title-main">Anterior tympanic artery</span>

The anterior tympanic artery is a branch of the maxillary artery. It passes through the petrotympanic fissure to entre the middle ear where it contributes to the formation of the circular anastomosis around the tympanic membrane. It provides arterial supply to part of the lining of the middle ear. It is accompanied by the chorda tympani nerve.

<span class="mw-page-title-main">Infratemporal fossa</span> Cavity that is part of the skull

The infratemporal fossa is an irregularly shaped cavity that is a part of the skull. It is situated below and medial to the zygomatic arch. It is not fully enclosed by bone in all directions. It contains superficial muscles, including the lower part of the temporalis muscle, the lateral pterygoid muscle, and the medial pterygoid muscle. It also contains important blood vessels such as the middle meningeal artery, the pterygoid plexus, and the retromandibular vein, and nerves such as the mandibular nerve (CN V3) and its branches.

<span class="mw-page-title-main">Mandibular fossa</span> Depression in the temporal bone that articulates with the mandible

The mandibular fossa, also known as the glenoid fossa in some dental literature, is the depression in the temporal bone that articulates with the mandible.

<span class="mw-page-title-main">Intermediate nerve</span> Portion of the facial nerve

The intermediate nerve, nervus intermedius, nerve of Wrisberg or Glossopalatine nerve, is the part of the facial nerve located between the motor component of the facial nerve and the vestibulocochlear nerve. It contains the sensory and parasympathetic fibers of the facial nerve. Upon reaching the facial canal, it joins with the motor root of the facial nerve at the geniculate ganglion. Alex Alfieri postulates that the intermediate nerve should be considered as a separate cranial nerve and not a part of the facial nerve.

<span class="mw-page-title-main">Outline of human anatomy</span> Overview of and topical guide to human anatomy

The following outline is provided as an overview of and topical guide to human anatomy:

References

PD-icon.svgThis article incorporates text in the public domain from page 140 of the 20th edition of Gray's Anatomy (1918)

  1. Petrotympanic+fissure Archived October 9, 2016, at the Wayback Machine at eMedicine Dictionary
  2. Eckerdal O (1991). "The petrotympanic fissure: a link connecting the tympanic cavity and the temporomandibular joint". Cranio. 9 (1): 15–22. doi:10.1080/08869634.1991.11678343. PMID   1843474.
  3. "Glaserian fissure". Medcyclopaedia. Retrieved 2008-03-07.[ dead link ]