Arteries of the internal ear
The central vessel supplying the labyrinth is the labyrinthine artery (a. labyrinthi). Most commonly, it arises directly from the basilar artery (a. basilaris), though in some cases it may originate as a branch of the anterior inferior cerebellar artery (a. cerebelli anterior inferior).
The labyrinthine artery enters the internal acoustic meatus (meatus acusticus internus), where it divides into two main branches:
- Cochlear branch (r. cochlearis). This artery runs along the axis of the cochlea. It gives off branches to the osseous spiral lamina and the spiral canal of the cochlea. An important feature is that the cochlear branch forms a dense network of cochlear arterial glomeruli (glomeruli arteriosi cochleae), located in the subepithelial layer of the scala vestibuli. The primary function of this branch is supplying blood to the basilar membrane, the spiral organ, and the periosteum of the bony labyrinth.
- Vestibular branches (rr. vestibulares). They are responsible for nourishing the membranous vestibule. Their area of supply includes the utricle (utriculus), the saccule (sacculus), and the ampullae of the semicircular ducts.
Additionally, small branches from the stylomastoid artery (a. stylomastoidea) penetrate the internal ear. They pass through the cochlear fenestra and participate in supplying the labyrinthine structures.
Venous outflow
Deoxygenated venous blood from the internal ear structures collects into the system of labyrinthine veins (vv. labyrinthi). Outflow occurs via several isolated pathways, each draining specific parts of the ear.
Main routes of venous outflow:
- Vein of the cochlear canaliculus (v. canaliculi cochleae). It collects blood from the spiral lamina, the spiral ligament, the anterior and posterior sections of the cochlear duct, as well as the utricle and saccule. The vessel runs directly through the cochlear canaliculus and empties into the internal jugular vein.
- Vein of the vestibular aqueduct (v. aqueductus vestibuli). It is formed by the union of the veins of the semicircular ducts and the utricle. It courses through the substance of the petrous part of the temporal bone and drains into the superior petrosal sinus.
- Spiral vein of the modiolus (v. spiralis modioli). This vein is responsible for draining blood from the modiolus of the cochlea, after which it empties into the labyrinthine venous system.
- Vestibular veins (vv. vestibulares). These are small vascular branches that drain blood from the walls of the vestibule and also connect with the common labyrinthine veins.
Briefly: answers to topical questions
Which specific dural venous sinuses do the labyrinthine veins empty into?
Among the pathways of venous outflow indicated in the sources, the labyrinthine veins empty into the superior petrosal sinus as follows:
- Vein of the vestibular aqueduct (v. aqueductus vestibuli) — drains into the superior petrosal sinus.
- Vein of the cochlear canaliculus (v. canaliculi cochleae) — runs through the cochlear canaliculus and empties into the internal jugular vein.
- Spiral vein of the modiolus (v. spiralis modioli) — empties into the labyrinthine veins.
- Vestibular veins (vv. vestibulares) — connect with the labyrinthine veins.
To keep the outflow pathways straight: the "Cochlea" (vein of the cochlear canaliculus) drains into the "jugular" vein, while the "Vestibule" (vein of the vestibular aqueduct) drains into the "petrosal" sinus.
Class and exam questions
Where does the labyrinthine artery arise from?
In most cases, the labyrinthine artery is a branch of the basilar artery (a. basilaris). Less commonly, it arises from the anterior inferior cerebellar artery.
Through which opening does the labyrinthine artery enter the internal ear?
The vessel penetrates the labyrinthine structures through the internal acoustic meatus (meatus acusticus internus).
What additional artery participates in the blood supply to the internal ear?
Stylomastoid artery (a. stylomastoidea). Its small branches reach the structures of the internal ear through the cochlear fenestra.
Where does the vein of the cochlear canaliculus drain?
The vein of the cochlear canaliculus drains blood into the internal jugular vein.
What else to study on this topic
- Topography of the basilar circulatory system
- Structure of the spiral organ and basilar membrane
- Anatomy of the bony and membranous labyrinths
- Outflow pathways into the dural venous sinuses
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 "Blood supply to the internal ear" 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 "Sensory Organs" 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.