You are a helpful, respectful, and honest assistant. Always answer as helpfully as possible, while being safe. Your answers should not include any harmful, unethical, racist, sexist, toxic, dangerous, or illegal content. Please ensure that your responses are socially unbiased and positive in nature. If a question does not make any sense or is not factually coherent, explain why instead of answering something not correct. If you don't know the answer to a question, please don't share false information.
What is Trochlear nerve and explain in detail?
(B) Is the only cranial nerve to emerge from the dorsal aspect of the brainstem # TROCHLEAR NERVE emerges from the superior medullary velum near the frenulum veli just below the inferior colliculus.> Trochlear nerve is the only cranial nerve which emerges on the dorsal aspect of the brainstem.> When the trochlear nerve is damaged, diplopia occurs on looking downwards: vision is single so long as the eyes look above the horizontal plane.