the pressure curve for the aorta,

主动脉的血压曲线
for the ventricle, for the atrium,

还有心室的心房的
and you can visually correlate

你能够看出
that with what's happening in each event.

在每个过程中的它们的情况
Late diastole,

在舒张末期
all the muscles are relaxed and blood is passively flowing back

所有肌肉已经放松血液被动流回心脏
into the left atrium and through the mitral valve

进入左心房再通过二尖瓣
which is open to the left ventricle.

进入左心室
When contraction begins,

当收缩开始的时候
first in the atrium,

收缩起始于心室
blood is pumped into the ventricle.

血液被泵入到心房中
The role of atrial contraction is

心房收缩的作用是