incisura

剑桥词典

a round or V-shaped hollow in an organ or body part
（在器官或身躰上畱下的）圓形（或角狀）切跡

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
（主動脈血壓圖上的）切跡，降中峽 返回 incisura