Citation, DOI & article data
The olfactory nerve is the first (CN I) cranial nerve (TA: nervus olfactorius or nervus cranialis I) and is responsible for conveying the sense of smell from the nasal cavity to the brain. Along with the optic nerve, it is actually a peripheral extension of the central nervous system.
- location: olfactory groove; anterior cranial fossa near the midline
- branches and supply: 20 or so olfactory filaments in the roof of the nasal cavity
The bipolar cell is the first-order sensory neuron located in the roof of the nasal cavity, immediately inferior to the cribriform plate of the ethmoid bone. This cell is analogous to the sensory cells of spinal nerves, whose cell bodies reside in the dorsal root ganglion.
Their central processes form filaments (~20) which pass through the cribriform plate, pierce the dura mater and relay in the olfactory bulb, the expanded anterior portion of the nerve that sits in the olfactory fossa.
The central process of these second-order neurons forms the olfactory tract which courses posteriorly, superior to the olfactory groove of the anterior cranial fossa, and inferior to the olfactory sulcus (lateral to gyrus rectus, and medial to the orbital gyri).
Anterior to the anterior perforated substance, they form medial and lateral olfactory striae. The lateral olfactory striae project to the uncus. The medial olfactory striae ultimately project to the hypothalamus and brainstem nuclei.
Coronal images are the best to depict the olfactory nerve as it is situated deep in the olfactory groove.
- 1. Chummy S. Sinnatamby. Last's Anatomy. (2011) ISBN: 9780702033957 - Google Books
- 2. Carmine D. Clemente. Anatomy. (2011) ISBN: 9781582558899 - Google Books
- 3. Sheth S, Branstetter B, Escott E. Appearance of Normal Cranial Nerves on Steady-State Free Precession MR Images. Radiographics. 2009;29(4):1045-55. doi:10.1148/rg.294085743 - Pubmed
- 4. FIPAT. Terminologia Anatomica. 2nd Ed. FIPAT.library.dal.ca. Federative International Programme for Anatomical Terminology, 2019. https://fipat.library.dal.ca/TA2/