Final answer:
The olfactory nerve (CN I) function is assessed through a sense of smell test, which involves identifying common odors presented to one nostril at a time. Successful identification indicates proper nerve function, while anosmia suggests dysfunction which may be temporary or permanent, depending on the extent of damage.
Step-by-step explanation:
The function of the olfactory nerve (CN I) is typically assessed by using a sense of smell test. This simple test involves presenting common smells to one nostril at a time to see if the patient can recognize them, such as the smell of coffee or mint. If the patient is able to identify the odors, it indicates that the olfactory nerve is functioning properly. An inability to smell, known as anosmia, may occur due to various reasons, including blunt trauma or aging, as the short axons of the olfactory nerve have the capacity for regeneration, and this function is an example of the limited regenerative abilities in the mature nervous system.