Structure and Function of the Olfactory Nerve
- The olfactory nerve is the first cranial nerve.
- It contains sensory nerve fibers related to the sense of smell.
- The olfactory nerve originates in the olfactory mucosa in the nasal cavity.
- It travels through the cribriform plate of the ethmoid bone to reach the brain.
- The olfactory nerve is not visible on a cadaver brain.
- The olfactory nerve transmits sensory stimuli in the form of odorants.
- It encodes odorants into electrical signals.
- The olfactory nerve relays olfactory information to higher-order centers in the brain.
- It works to ensure the identification and distinction of various odorants.
- Odorants interact with olfactory receptor neurons to initiate olfaction.

Odor Transduction
- Odorants bind to specific odorant receptor proteins on olfactory cilia.
- This binding evokes an electrical response in olfactory receptor neurons.
- Olfactory receptor molecules consist of trans-membrane domains and a cytoplasmic domain.
- Activation of adenylate cyclase leads to an increase in cyclic AMP.
- Depolarization of the neuron occurs through ion channels and generates an action potential.

Regeneration of Olfactory Nerves
- Olfactory receptor neurons can be damaged by inhaled substances.
- The olfactory epithelium consists of supporting cells, mature ORNs, and basal cells.
- Basal cells divide to produce new receptor neurons for regeneration.
- ORNs undergo a cycle of degeneration and regeneration.
- The regeneration process is unique to ORNs.

ORN Specificity
- Odorant molecules interact with receptor proteins on localised neuronal cilia.
- Each olfactory receptor neuron expresses one type of protein receptor.
- Mature ORNs have decreased expression levels of multiple olfactory receptor genes.
- Different odors activate specific ORNs in a molecular and spatial manner.
- ORNs can have high affinity and selectivity for specific odorants.

Additional Information and References
- Additional images: Olfactory nerve, deep dissection, inferior view.
- Related topics: Wikimedia Commons has media related to Nervus olfactorius, anterior olfactory nucleus, phantosmia.
- References: Various sources including textbooks and scientific articles on anatomy, physiology, and neuroscience.