In this plastinated cadaver, the vertebral arches have been removed to reveal the spinal cord inside the canal. Note how the solid spinal cord becomes a loose collection of nerves (the cauda equina) in the lumbar region.
The spinal cord stops growing in childhood even though the vertebral column does not.
In adults, the spinal cord stops around the level of the first lumbar vertebra (L1). Spinal nerves continue downward as the cauda equina (“horse’s tail”), a bundle of nerves that contains the last lumbar nerves (L2-L5) and all the sacral and coccygeal nerves.
The filum terminale (“terminal thread”) is a strand of modified pia mater that tethers the end of the spinal cord to the coccyx.
I just need everyone to know how much I really, really, REALLY hate Aristotle.
And there are three kinds of hatred for Aristotle, the first being visceral, so called because it rises from the intestines and through the middle of a person, yet never wanes nor increases but remains constant; and the second is called passive, and this occurs when a scholar or reader comes upon the works of Aristotle by chance, without seeking them out of their own volition, but rather confronted with them unexpectedly as a man set upon by bandits along a lonely road, but this sort of anger passes quickly; but indeed the third is active, and this occurs when a person seeks out Aristotle with the particular intention of becoming choleric; this sort of person seeks out the works of Aristotle wherever they may be found so that they might read them and thereby conjure up some bilious reason to cast invective and rebuke upon his theories and observations, and this anger is kept by its possessor at a boil.
And yet all this pales next to my hatred of Plato. My perfect, unchanging hatred.
You know that whole trope where like, the protagonists get teleported up into the aliens’ spaceship or base or whatever and the alien appears to them only it doesn’t appear as it really looks like but rather, since it doesn’t want to scare the protagonists, it takes the form of something we find familiar and pleasing and is like, “I look like your dad or whatever–is this form okay?” Like I think about that trope a lot and I think like, what if the alien couldn’t pick out a form via telepathy and only had earth media to try and decide what form would scare its human guests least and be accepted almost immediately and honestly the more I think about it the more options for what form that might be are just really fun to me.
“I have chosen the form of your earth playwright and composer Lin-Manuel Miranda–do not be afraid. I come in peace.”
“Greetings. I am Glofnorbo of the cloud you call the ‘Pegasus Nebula.’ I have scanned your earth media from afar and empirically decided that you would find the form of the one known as Dwayne ‘The Rock’ Johnson most pleasing. I have come to confer with your leaders.”
“Do not be panic. I come in peace. I have assumed the form of your insectoid demigoddess ‘Hatsune Miku’ so that we may communicate peacefully without my true form horrifying you.”
“It was decided that I would assume the form of your ‘Mister Rogers’ in order to best welcome your world to the galactic neighborhood without frightening your kind.”
