Relating to both the auricle and ventricle of the heart; describing the relationship between the upper and lower chambers.
From auriculo- (auricle, a heart chamber) combined with ventricular (relating to the ventricle, another heart chamber). This term is largely historical, as modern medicine uses atrioventricular.
This is basically old-school medical terminology that's been replaced by 'atrioventricular,' but it shows how anatomists originally thought the ear-shaped auricle was similar enough to name the heart chamber after it!
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