The aorta is the largest ARTERY in the human body, and it is responsible for carrying oxygen-rich blood from the heart to the rest of the body. The term 'aorta' can be broken down into two parts: 'aor' and 'ta'. The crossword solutions for these two parts are 'ARTERY' (6 letters) and 'innertube' (9 letters). Together, these two words form the term 'aorta', which is an important part of the cardiovascular system.