The Spanish word 'mitocondria' comes from New Latin 'mitochondria' (plural of 'mitochondrion'), which was formed from two Ancient Greek words: 'mitos' (μίτος) meaning 'thread or filament' and 'khondros' (χόνδρος) meaning 'granule or grain'. This scientific term was created to describe these tiny thread-like granular structures found in cells, reflecting their appearance under a microscope.

Since 'mitocondria' is a relatively recent scientific term borrowed directly from New Latin, there aren't many simpler or more common Spanish words that share its etymology.

The English word 'mitochondrion' (plural: mitochondria) is directly related to the Spanish 'mitocondria', as both come from the same New Latin term. The only difference is that Spanish adapted the spelling to match its phonetic rules by dropping the 'h'. English also uses related terms like 'mitochondrial' in scientific contexts. Understanding this connection can help English speakers remember that this is essentially the same word in both languages, just with slightly different spelling.