Relating to a miter (a bishop's ceremonial hat) or the mitral valve in the heart shaped like one.
From Latin 'mitra' meaning 'headband' or 'turban,' borrowed from Greek. The medical use came from the heart valve's resemblance to a bishop's pointed hat.
Medieval doctors were so creative with naming—they saw a heart valve that looked like a bishop's fancy hat and named it accordingly! Many medical terms come from this kind of visual comparison-naming by early anatomists.
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