First, some background:

• Doctors generally all clamp the cord at about the same place, so it doesn’t play off tying technique, and there isn’t time to ask for preference during delivery anyways, as it’s recommended that the cord be clamped a mere 20-30 seconds after the baby is out of the uterus.
• We generally start with bellybuttons that resemble outies, but as the subcutaneous fat layer develops under the skin around the umbilicus, they “pop in” to become your typical innie.
• There’s discussion on whether post-natal umbilical hernias cause outies; I don’t know much about this particular condition, but I’m a bit skeptical–hernias will inflate/deflate with simple breathing, and while I suppose they could increase the chances of an outie after treatment, I doubt it’s significant.

The physiologic basis is the baby’s vasculature!

Every baby comes into this world with an umbilicus that can be represented like so, where “||” represents skin and “=” represents cord:
||
=========
||

When the cord is clamped upon the baby’s birth, the umbilical arteries and veins that run its length naturally constrict in response and shrivel, causing the cord to atrophy and fall off. In most people, it ends up looking like this:
||
==
||

The cord falls off at about the level of skin, and the 2nd bullet point above takes care of the rest to create an innie:
|fat|
==
|fat|

In some people, however, a longer chunk of their umbilical vasculature stays open, keeping slightly more tissue perfused and alive:
||
=====
||

You can see how this would create an outie:
|fat|
=====
|fat|

What factors encourage that extra skin for the outie to stay, no one knows, you might as well ask why most people are right handed but some people end up left.

Back when I first discovered the beauty of the screwdriver and its magical ability to take things apart and show me the inner workings of whatever poor piece of technology I tackled, my father gave me a piece of advice: “It doesn’t mean anything to be able to take something apart if you can’t restore it to its original whole.”

I must’ve taken apart just about everything in the house except maybe the kitchen oven and refrigerator (mainly because, well, I didn’t have the guts to stand up to my mom when she said no, and even in my foolish youth I had the wisdom not to do anything that might impede the process of food reaching my mouth). But clocks, radios, an old TV, various computers, and every other random gadget I could get my hands on fell to the sharp blade of my flathead. I was convinced I was going to be an engineer who would invent the flying car one day. At least, that’s what I told myself as I played with my Legos. This was until I took calculus.

Fast forward 15 years, and I find myself not in a machining shop, but in an anatomy lab. Working not with big power tools, but with a scalpel and some green pokey things. And the environment is just…utterly bizarre. We joke around a lot in anatomy lab. Anyone who isn’t in medical school or gone through it simply wouldn’t understand. How is it even possible to attempt humor or liveliness whilst surrounded by the presence of the dead? But in many ways–we have to, or else it would drive us mad. As if the sleep-deprived hours spent cramming the material before the lab closes for exam preparation weren’t enough, if we had to be stone-cold somber the entire time it would be unbearable. So we kid, we jibe, we toss insults back and forth about whose body has the larger penis, and so on.

But even as we complain about the havoc the smell wreaks through our first cranial nerve, even as we dehumanize an entity that is so entirely human, we remain quite aware that these cadavers are our best tool for learning ourselves–that ironically, we must learn from the dead to treat the living. Every time I mistakenly cut something I felt terrible for ruining an opportunity to learn from my donor. I imagine that maybe they’re around in spirit. I imagine that honestly, they’re probably kind of horrified at what their physical beings are subjected to. But I also imagine that somewhere amidst that shock they remember why they agreed to donate. Why they agreed to posthumously teach us for months when they could have been peacefully laid to rest for eternity. Why they agreed to an act of kindness that will ultimately impact thousands of fellow men, women and children as each of us graduates and begins a career of healing.

It bugs me that I can’t follow my father’s advice in this case. I will never be able to restore my cadaver to its whole pristine state. And while I hope this only gives us all more motivation to work to restore our future patients to their happy healthy selves, I can’t help but wish I were able to thank our donors more tangibly. I imagine that perhaps some of our donors spirits are with us now as we acknowledge and pay tribute to their incredible sacrifice. I hope they understand just how thankful we are to have been given such a privileged blessing. I will never know the identity of the person whose body I dissected, beheaded, and in many ways, due to my inexperience, mangled. I will never know whose sister, aunt, mother, grandmother, daughter I cut apart. I can only hope that my belief in a divine power is not unfounded as I pray He deliver our thanks to these generous souls for bringing us first-years to a closer understanding of God and man.