Left Atrium 左心房 The atria of the heart, which are known singularly as an atrium, are a pair of blood collecting chambers that comprise two of the four chambers of the heart.心脏的心房（单数形式：atrium，复数形式：atria）是一对血液收集腔室，它由心脏 4 个腔室中的 2 个组成。 The main function of the atria is to facilitate circulation by rhythmically contracting and relaxing their walls, pushing the blood that is returned to them via the major venous vessels during ventricular systole into the ventricles.心房的主要功能是通过有节律地收缩和松弛心房壁来促进血液循环，在心室收缩期，通过主要静脉血管推动返回心房的血液进入心室。 In this tutorial, we will focus on the left atrium.在这个教程中，我们将重点介绍左心房。 The left atrium, as seen here, highlighted in green, on the diaphragmatic surface of the heart, is responsible for collecting the outflow of oxygenated blood that runs back to the heart from the pulmonary veins. 如图中绿色区域所示，左心房在心脏横膈膜表面，负责收集从肺静脉流回心脏的含氧血液。 It passes this volume of blood onto the left ventricle as the atrium contracts and the mitral valve opens.当心房收缩，二尖瓣打开时，心房将这些血液输送到左心室。 The mitral valve is also known as the bicuspid valve because it is formed by two septal cusps. Occasionally, it is also mentioned in literature as the left atrioventricular valve.之所以称为二尖瓣（mitral valve/bicuspid valve），是因为它由两个隔瓣组成。有时，在文献中也作左房室瓣。 The blood supply to the left atrium is governed by the left circumflex coronary artery, and it is drained by the oblique vein of the left atrium, which arises during embryonic development from the left side of the fetal superior vena cava.左心房的血液供应由左冠状动脉回旋支支配，由左房斜静脉引流，而左心房斜静脉在胚胎发育过程中，由胎儿左上腔静脉形成。 The main anatomical structure of note is the foramen ovale, which is a foramen within the atrial walls that allows blood to shunt between the two atria during embryonic development.大家需要注意，主要的解剖结构是卵圆孔，即胚胎发育期间，在两个心房之间分流血液的心房壁内的孔。 Normally, around the time of birth, this hole in the cardiac wall closes. 正常情况下，胎儿出生时，心脏壁上的这个孔会关闭。 Otherwise, it is known as a congenital heart defect named patent foramen ovale. It is not, however, generally problematic in child or adulthood.相反，如果这个孔未关闭则会导致先天性心脏病--卵圆孔未闭。然而，它对儿童或成人一般不会有明显的影响。 相关单词学习
Atrioventricular
①发音和释义 a•tri•o•ven•tric•u•lar/ˌeɪtrɪoʊven'trɪkjələ/adj. 房室的Of or pertaining to the atria and ventricles of the heart. 单词 atrioventricular 由下列成分构成 atrio-心房+ventricular 心室的（图源：太帅图库）
Circumflex
cir•cum•flex/ˈsɜːrkəmflɛks/adj. 旋绕的Bending or winding around. 单词 circumflex由下列成分构成 circum-（前缀） 环/围绕+flex 弯曲
《心脏听诊教学》（课时：7） 《心脏听诊教学》持续更新中（目前更新到第7节课）......涵盖听诊区、听诊器、听诊方法，S1心音等内容，适用于临床医生，医学生，及相关人士的医学教育，课程简短，知识点精炼，高效提高学习效率。All rivers run into sea. 海纳百川。 戳“阅读原文”，查看全部视频课程
