the.com/myocardium
The muscle that never clocks out — one job, three billion beats, zero vacations.
means The thick muscular middle layer of the heart wall, whose contractions actually pump the blood.
from Built from Greek 'mys/myo-' (muscle) plus 'kardia' (heart) — the same 'myo-' that shows up in myopathy and myosin, and the same 'cardia' behind cardiac and cardiology. It's a 19th-century anatomical coinage, stitched together the way most heart-and-muscle terms were: by naming exactly what it is, in two borrowed Greek pieces, rather than by any dramatic backstory.
- cell type
- striated like skeletal muscle, involuntary like your bowels
- self-wiring
- has its own electrical grid, skips brain entirely
- regeneration
- barely regrows, scars instead of healing
- oxygen hunger
- burns more oxygen per gram than any other organ