下か行こう大だい動どう脈みゃく

Meanings

1

noun

descending aorta

anatomy

Anatomical term for the portion of the aorta that descends through the thorax and abdomen.

move, motion, change

脈vein, pulse, hope

大だい動どう脈みゃく
大動脈 is the general term for the aorta; 下行大動脈 specifies the descending portion.
上じょう行こう大だい動どう脈みゃく
上行大動脈 is the ascending aorta, the opposite segment.

Compound of 下行 (descending) and 大動脈 (aorta), a direct anatomical calque.