The circle of Willis is a ring of connected arteries that supply blood to the brain. When the ring is intact, injury to a blood vessel on one side can, up to a point, and depending on the injury, be compensated for by the blood coming up to the brain from the other side and traveling around the circle of Willis. It's how people who have severe occlusion of a carotid due to atherosclerosis can still get some blood up there.
You know you've spent too much time in hospitals when the first thing you notice about people is their veins and what size IV would fit in them and the first thing that comes into your mind when a hockey player takes a skate blade to the neck is, "OMG is he okay?! Good thing his circle of Willis is intact!"
I'll try to list seven other "Wonders of the Anatomical World" here but if anyone thinks of any that I've spaced out on (beside obvious wonders like the brain), please feel free to chime in. I could probably come up with a whole other list...
7. The trabecular structure of bone.
6. The fine muscles of the hand.
5. The larynx (I'm an anesthesiologist - I have to love the larynx).
4. The ductus arteriosus (and I'm gonna cheat here and include the fetal circulation in general as well as the placenta)
3. The His-Purkinje system (cardiac conduction fibers)
2. The chemoreceptors in lung vasculature that cause blood vessels in the lung to dilate in response to oxygen, when all the other receptors in the body cause constriction.
1. Tiny sensors and transmitters: the cochlea and ossicles in the ear, and rods & cones in the retina (actually, the whole eye is pretty amazing)
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*The Canadian news video I had originally linked to has been removed. This is some American footage. I can't believe he got up and skated halfway down the rink and was able to get to the trainer, and I'm so glad he got help right away. I wish Mr. Zednik and his family well and bow my head in admiration toward Dr. Sonya Noor, who performed the repair, and all the docs, nurses, and techs at Buffalo General Hospital who helped take care of him.
That video is scary. I have often wondered why there weren't more gashes like that with the razor-like sharpness of the skates. The goalie was even more sad - no one was paying attention at first while he's exsanguinating.
ReplyDelete7 is a hard number to come up with - but I think you have some good choices.
I'm not so sure about the wonder of the Larynx and friends, but that may be because I'm sitting here between an ENT and a Gastroenterologist who are both pointing across the room at their colleague and crying "That's his problem" while every time I cough my airway closes up and I bruise the inside of my rib cage as the pressure in my chest seems to go from 1 atmosphere to 20. That would be an x-ray I'd like to see... a rib broken out from the inside.. Not to mention the occasional backwash of debris down into my lungs after a coughing fit.
ReplyDeleteThere are some amazing structural marvels in our anatomy, and some downright phenomenal chemical computing structures... but this multiplexed breathing/eating thing lacks an elegant redundancy.
I'm thinking of asking for gills next time.