The inferior tympanic artery is a small branch of the

ascending pharyngeal artery The ascending pharyngeal artery is an artery in the neck that supplies the pharynx, developing from the proximal part of the embryonic second aortic arch. It is the smallest branch of the external carotid and is a long, slender vessel, deeply sea ...

. It is a small branch which passes through a minute

foramen In anatomy and osteology, a foramen (;Entry "foramen"
in

in the

petrous portion of the temporal bone 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 an ...

which is called tympanic canaliculus or

inferior tympanic canaliculus The inferior tympanic canaliculus is a small passage of the tympanic branch of the glossopharyngeal nerve and inferior tympanic artery. In the bony ridge dividing the carotid canal from the jugular fossa is the small inferior tympanic canaliculu ...

, in company with the tympanic branch of the

glossopharyngeal nerve The glossopharyngeal nerve (), also known as the ninth cranial nerve, cranial nerve IX, or simply CN IX, is a cranial nerve that exits the brainstem from the sides of the upper Medulla oblongata, medulla, just anterior (closer to the nose) to t ...

, to supply the medial wall of the

tympanic cavity 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. Structure On its lateral surface, it abuts the external auditory ...

and anastomose with the other tympanic arteries.

Clinical Significance

In the case of a missing or underdeveloped cervical ICA, the Inferior tympanic artery can provide collateral ICA circulation by reversing flow of the caroticotympanic artery (embryologic hyoid artery). This can result in pulsatile tinnitus. The resulting Aberrant Carotid artery can mimic neoplasm on CT.

References

Arteries of the head and neck {{circulatory-stub