Inferior tympanic canaliculus
The inferior tympanic canaliculus is a small bony passageway that lies within the petrous portion of the temporal bone, between the carotid canal and jugular foramen.
Gross anatomy
The inferior tympanic canaliculus is a bony canal that separates the opening of the carotid canal anteromedially from the jugular foramen posterolaterally . It is also located medially to the stylomastoid foramen and the styloid process of the temporal bone.
Contents
The inferior tympanic canaliculus contains the inferior tympanic artery (branch of the ascending pharyngeal artery) in addition to the tympanic branch of the glossopharyngeal nerve (Jacobson nerve) as it passes through to the middle ear to form the tympanic plexus and subsequently the lesser petrosal nerve . Glomus bodies around the Jacobson nerve are also contained in the inferior tympanic canaliculus .
History and etymology
The inferior tympanic canaliculus is also referred to as "Jacobson's canal" and is named after Ludvig Levin Jacobson, a renowned anatomist from Copenhagen who in the early 1800s described the anatomy of the canal .
Related pathology
Several abnormalities of the neurovascular contents can smoothly enlarge the inferior tympanic canaliculus:
- aberrant internal carotid artery: collateral pathway involving inferior tympanic artery
- glomus jugulare paraganglioma: inferior tympanic artery may be hypertrophied supplying this hypervascular tumor
- Jacobson nerve schwannoma
Bony destruction of the inferior tympanic canaliculus can be caused by paraganglioma (glomus tumor) with extension into jugular fossa and tympanic cavity: glomus jugulotympanicum paraganglioma .
