Final answer:
Cranial nerves are a set of 12 nerves that serve the head and neck and can be sensory, motor, or both. They can be tested through a cranial nerve exam to assess various functions.
Step-by-step explanation:
The cranial nerves are a set of 12 nerves that emerge from or enter the skull (cranium) and serve the head and neck. The function of these nerves can be categorized as sensory, motor, or a combination of both. Some cranial nerves transmit only sensory information, such as the olfactory nerve for smell, while others transmit mostly motor information, like the oculomotor nerve for eye movements. There are also cranial nerves that contain a mix of sensory and motor fibers, like the glossopharyngeal nerve for taste and swallowing.
The function of the cranial nerves can be tested through a cranial nerve exam, which allows for directed tests of the structures in the brain stem and forebrain. The exam can assess sensory nerves, eye movement control, nerves of the oral cavity and pharynx, and movements of the neck.