MY friend mentioned that she was diagnosed with several brain tumours impinging on her brainstem. These tumours, she said, are likely to impinge upon her cranial nerves. What are cranial nerves?
There are twelve cranial nerves altogether. These are twelve pairs of nerve tissue that arise from the brain itself, rather than the spinal cord. In order to innervate their target organs, they must exit/enter the cranium through openings in the skull (cranium). Hence, they are called cranial nerves.
