Ted Chiang’s Exhalation is one of my favourite short stories. Its centrepiece is a meticulous description of the protagonist’s self-dissection of his own brain. It’s a mechanical being (although the word mechanical seems too crude) so rather than blood and bone, it’s an assemblage of intricate mechanisms. Reading it takes some concentration — you really have to pay attention to each word and try to hold the image in your head as each detail is added — but it’s well worth the the effort.
When I was done, my brain looked like an explosion frozen an infinitesimal fraction of a second after the detonation, and again I felt dizzy when I thought about it. But at last the cognition engine itself was exposed, supported on a pillar of hoses and actuating rods leading down into my torso. I now also had room to rotate my microscope around a full three hundred and sixty degrees and pass my gaze across the inner faces of the subassemblies I had moved. What I saw was a microcosm of auric machinery, a landscape of tiny spinning rotors and miniature reciprocating cylinders.
You can find the story online at the Night Shade Books site, or in Chiang’s recent collection, also called Exhalation.