Where does the labyrinthine artery arise from?
The labyrinthine artery belongs to the vertebrobasilar system, the vessels of which, along with the elements of the circle of Willis, participate in the blood supply to the brainstem and adjacent structures.
- Main origin variant: most commonly, the vessel arises directly from the basilar artery (a. basilaris), an unpaired trunk formed by the union of the two vertebral arteries.
- Alternative origin variant: less commonly, the labyrinthine artery may originate from the anterior inferior cerebellar artery (a. cerebelli inferior anterior), which branches off the basilar artery.
Topography and course
The labyrinthine artery runs toward the inner ear (auris interna).
- Internal acoustic meatus (meatus acusticus internus): the vessel enters this meatus, which is directed from medial to lateral.
- Contents of the meatus: along with the labyrinthine artery, the meatus contains the facial nerve (n. facialis, cranial nerve VII), intermediate nerve (n. intermedius), and vestibulocochlear nerve (n. vestibulocochlearis, cranial nerve VIII). The labyrinthine artery passes through the meatus acusticus internus along with the n. vestibulocochlearis to the inner ear.
What branches does the artery divide into?
Within the internal acoustic meatus, the labyrinthine artery divides into cochlear and vestibular branches.
- Cochlear branch (r. cochlearis) runs along the axis of the cochlea. It gives off branches to the spiral canal of the cochlea and the osseous spiral lamina. In the subepithelial layer of the scala vestibuli, this branch forms numerous arterial glomeruli of the cochlea (glomeruli arteriosi cochleae). The cochlear branch supplies the basilar membrane, spiral organ, and the periosteum of the bony labyrinth.
- Vestibular branches (rr. vestibulares) supply the membranous vestibule, nourishing the utricle (utriculus), saccule (sacculus), and ampullae of the semicircular ducts.
Structures of the inner ear supplied with blood
The inner ear is located in the petrous part of the temporal bone between the tympanic cavity and the internal acoustic meatus. Its blood supply is provided by the labyrinthine artery.
- Bony labyrinth (labyrinthus osseus): comprises the vestibule located centrally, the cochlea anterior and medial to the vestibule, and the osseous semicircular canals posterior and lateral. The osseous semicircular canals—anterior, posterior, and lateral—communicate with the vestibule via 5 openings.
- Membranous labyrinth (labyrinthus membranaceus): connective tissue structure enclosed within the bony labyrinth, mirroring its shape but smaller in volume. It contains endolymph.
- Perilymphatic space: a cleft between the bony and membranous labyrinths, filled with perilymph.
Additional blood supply and venous drainage: besides the labyrinthine artery, small branches of the stylomastoid artery (a. stylomastoidea) pass through the fenestra cochleae to reach the structures of the inner ear. Venous drainage is directed into the superior and inferior petrosal sinuses.
Class and exam questions
Which artery does the labyrinthine artery most commonly arise from?
Most commonly, it is a branch of the basilar artery (a. basilaris), less frequently of the anterior inferior cerebellar artery.
With which nerves does the labyrinthine artery enter the internal acoustic meatus?
Within the internal acoustic meatus, along with the labyrinthine artery, are the facial nerve (n. facialis, cranial nerve VII), intermediate nerve (n. intermedius), and vestibulocochlear nerve (n. vestibulocochlearis, cranial nerve VIII).
Which structures are supplied by the vestibular branches of the labyrinthine artery?
They supply the membranous vestibule, nourishing the utricle (utriculus), saccule (sacculus), and ampullae of the semicircular ducts.
Do other arteries participate in the blood supply to the inner ear?
Yes, small branches of the stylomastoid artery (a. stylomastoidea) pass through the fenestra cochleae to the structures of the inner ear.
What else to study on this topic
- Basilar artery (a. basilaris)
- Internal acoustic meatus (meatus acusticus internus)
- Inner ear (auris interna)
- Vestibulocochlear nerve (n. vestibulocochlearis)
Study the complete topic in the Anatomy course
This is a summary. The course covers everything tested in classes and exams.
- Complete study guide on "Labyrinthine artery" and 1,363 other subject pages
- Assignments and quizzes after every topic — just like in a colloquium
- AI tutor answers questions on the topic anytime
- 295 video lessons by subject
Other topics in the "Anatomical Structures" section
Free video lessons: AnatomyShort lessons with study notes — no registration required.
Prepared by WhiteCoat Pro faculty in accordance with the medical school curriculum. For educational purposes only.