The superficial tissues covering the skull, including the scalp and the underlying muscles and fascia.
From Greek 'epi-' (upon) + 'kranion' (skull) + '-ium' (Latin noun ending). Medieval anatomists used this term for the entire outer layer of the head.
The epicranium is why scalp wounds bleed so much—it's packed with blood vessels that supply the brain, and evolution prioritized keeping your head warm and protected over easy healing.
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