incisura

剑桥词典

a round or V-shaped hollow in an organ or body part
（在器官或身体上留下的）圆形（或角状）切迹

in a graph of the blood pressure in the aorta , a place where the curve goes slightly downwards and quickly up again just before the aortic valve closes
（主动脉血压图上的）切迹，降中峡 返回 incisura