Well I’ll have to look it up now, but I see it as a substance produced by the body that isn’t made of cells itself. Like any of the other excretions and things the body makes.
Edit: apparently both your nails and hair are mostly made of keratin, but keratin isn’t produced and excreted to produce the nail and hair structures like a playdough factory like I imagined. Special cells are produced that are primarily keratin and they are added to like a chain and die/harden as they are pushed out from the body.
Are you implying that your fingernails were never cells of your body? How does that work?
Well I’ll have to look it up now, but I see it as a substance produced by the body that isn’t made of cells itself. Like any of the other excretions and things the body makes.
Edit: apparently both your nails and hair are mostly made of keratin, but keratin isn’t produced and excreted to produce the nail and hair structures like a playdough factory like I imagined. Special cells are produced that are primarily keratin and they are added to like a chain and die/harden as they are pushed out from the body.
That is absolutely fascinating. I had the same assumption.