Something valuable I learned in block 4 dispelled a myth I heard throughout my childhood years – you can’t sneeze with your eyelids open or else your eyeballs will pop out. I even went as far as wondering how patients undergoing extensive eye surgery (ie, Lasik) can manage to have their eyelids held open without sneezing. What if they really, really had to?!
Come to find out, the main reason why we instinctively close our eyelids in response to a sneeze is to prevent regurgitation of fluids draining into our sinuses. In fact, after exploring the pharynx anatomy, I’m once again amazed by how elegantly our body follows the “structure-function” mantra.
Mucus from the ear canal and nasal cavity, tears produced by the lacrimal gland, and saliva used to initiate chemical digestion all find their way to the back of the oropharynx and ultimately down into the stomach via the esophagus. With all these fluids intermixing in such a small region, a sneeze could easily propel the contents back up the nasolacrimal duct into our eyes (at least according to one of the anatomy gurus at BCM). To prevent this retrograde movement, we close our eyes. 🙂
“I’m once again amazed by how elegantly our body follows the “structure-function” mantra.”
Hey Rishi! So, now that you are cutting cadavers open and whatnot, what are your thoughts on the human body? Does it seem to incline more as being “perfected” by evolution or did our Creator really knew what he was doing, Him having mad designing skills? Have you run into questionable organ system layout or bad piping, or is everything laid out as best as it possibly can be?
It’s a bit of both. Quite honestly, I find the human body to be the quintessential example of mechanical and biological perfection. Thousands of years of evolution have gone into “selecting” for the most efficient configurations (with the least waste), and consequently, practically every structure has more than one function. I do believe that some higher power put time and science into motion, but natural selection is responsible for the marvel that is the human body today.