Viswanathan K's Thoughts

Here’s how Nathan Lent describes a nerve in Human Errors : “Nerves are bundles of tiny individually wrapped cables called axons that convey impulses from the brain to the body (and vice versa).”   Take the nerve with the initials RLN (Recurrent Laryngeal Nerve), which connects the brain to the larynx (voice box). Given how close the brain is to the voice box in your neck, you’d think the RLN would be a few centimetres long. But no. Instead, it winds its way from the brain to the upper chest, loops under the aorta (heart area) and reaches the voice box! “The RLN is more than three times longer than it has to be. It winds through muscles and tissue that it need not.”   There is no functional benefit, so why does the RLN “travel this long, lonely road”? For the answer, we need to start with the ancient fish, which is where this nerve originated. From where it continued in all vertebrates. In those ancient fish, the RLN connected the brain to the ancestor of the voice ...