As I complete another journey around the sun, I give a brief pause to think that what I was a year ago has likely died off and but a distant memory. But never fear, this is not going to turn into the "philosophy thought of the day," I really don't have the patience for that. Rather, apoptosis, from the Greek 'falling away from', is the natural process in the cellular lifecycle in which a cell dies. It is different from necrosis in that it is generally not preceded by some acute trauma.
In general, apoptosis is a fairly understudied cellular process (at least compared to respiration, mitosis / meiosis, etc...) Theories exist about the triggers ranging from mitochondrial events to signal transducing adapter proteins (the later of which could be a months worth of topics in and of itself).
When the cell gets the piratical black mark, it ends up going through a fairly standard process of shrinking, nuclear pyknosis, and karyorrhexis (I challenge everyone here to use that in Scrabble). The breakdown produces apoptotic bodies which are then absorbed by phagocytes. When this process happens faster than cell reproduction, it is known as atrophy, and slower can occur in cases of cancer.
Just to show that death isn't always a bad thing, without apoptosis during embryonic development, we'd all be wearing mittens instead of gloves, or perhaps get our own feature role in the destruction of the greater Philly region (extra points for the movie buff that pulls off this reference).
Which takes me around full circle to what got me thinking about this all in the first place... How many cells have I burned through to date?? While there is not a one size fits all answer, I am going to have to approximate that I'm somewhere in the neighborhood of 7.38 x 10^17 cells.
Now considering most of these dead cells slough off, as I make the next orbit on Spaceship Earth, I shall remind myself to invest in cleaning products and dust rags.
Time for a drink to celebrate 🙂