Facial canal
Canalis facialis
- Latin synonym: Canalis nervi facialis
- Latin eponym: Canalis facialis Falloppii
- Eponym: Fallopian canal
Definition
The facial canal, also known as the Fallopian canal, is a Z-shaped channel situated in the petrous part of the temporal bone. It originates at the internal acoustic meatus and extends to the stylomastoid foramen.
Three important structures enter the facial canal via the internal acoustic meatus: the facial nerve, the vestibulocochlear nerve, and the labyrinthine artery. The facial nerve traverses this canal, coming out at the skull’s base through the stylomastoid foramen. Inside the canal, the path of the facial nerve is split into three segments by two bends. The initial segment, the labyrinthine part, runs sideways or laterally above the vestibule before bending backward at a point known as the geniculum of the facial canal. Following this bend, the second segment, the tympanic part, begins and proceeds backwards along the medial wall of the tympanic cavity, over the promontory. The facial canal makes another turn behind the promontory and then descends vertically down as the third segment, the mastoid part, culminating at the stylomastoid foramen.
As the facial nerve advances through the facial canal, it emits three primary nerve branches: the greater petrosal nerve, the nerve to the stapedius muscle, and the chorda tympani nerve.
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Text written by Muhammad A. Javaid, MD, PhD © 2024 IMAIOS.
Drake, R.L., Vogl, A.W. and Mitchell, A.W.M. (2009). ‘Chapter 8: Head and Neck’ in Gray’s anatomy for Students. (2nd ed.) Philadelphia PA 19103-2899: Elsevier, pp. 917-919 & Fig. 8.124 (A, B).
Standring, S. and Gray, H. (2016). ‘Chapter 37: External and middle ear’ in Gray’s anatomy The anatomical Basis of Clinical Practice. (41st ed.) New York: Elsevier, pp. 639 & Fig. 37.14.
