|Transverse section of the cochlear duct of a fetal cat. (Ganglion spirale is labeled at top, second from left.)|
|Part of the cochlear division of the acoustic nerve, highly magnified.|
|Gray's||subject #228 1051|
The spiral ganglion is the group of nerve cells that serve the sense of hearing by sending a representation of sound from the cochlea to the brain. The cell bodies of the spiral ganglion neurons are found in the spiral structure of the cochlea.
The rudiment of the acoustic nerve appears about the end of the third week as a group of ganglion cells closely applied to the cephalic edge of the auditory vesicle. The ganglion gradually splits into two parts, the vestibular ganglion and the spiral ganglion. The proximal fibers of the spiral ganglion form the cochlear nerve.
Spiral ganglion cells are strung along the bony core of the cochlea, and are part of the central nervous system. These spiral ganglion cells are bipolar first-order neurons of the auditory pathway of the brain. Their dendrites make synaptic contact with the base of hair cells, and their axons are bundled together to form the auditory portion of the VIII Cranial Nerve. In humans, the central axons number about 35,000 on each the left and right side. The acoustic information sent by this cranial nerve is very focused.
- Slide and overview at anatomy.dal.ca
- Slide at cytochemistry.net
- Image at University of New England, Maine
This article was originally based on an entry from a public domain edition of Gray's Anatomy. As such, some of the information contained herein may be outdated. Please edit the article if this is the case, and feel free to remove this notice when it is no longer relevant.