評論
打印
Four valves keep the blood moving in the appropriate direction. Two of the heart's valves separate the right and left atrium from the right and left ventricles. Two other valves separate the right ventricle from the pulmonary artery and the left ventricle from the aorta.
四組瓣膜使血液以合適的方向流動。其中兩組將左右心房與左右心室分開。另兩組瓣膜分別將右心室到肺動脈、左心室和主動脈分開。
During a normal heartbeat, oxygen-poor blood returning from the body enters the right atrium through the vena cava. The right atrium contracts, pushing blood through the tricuspid valve and into the right ventricle.
在一個心動周期中，機體的乏氧血液通過腔靜脈進入右心房。右心房收縮，將血液通過三尖瓣推入右心室。
Next, the right ventricle contracts to pump blood through the pulmonic valve and into the pulmonary artery, which connects to the lungs. At the same time, oxygen-rich blood returning from the lungs is delivered to the heart through the pulmonary veins.
接著，右心室收縮，將血液通過肺動脈瓣推入肺動脈，肺動脈連接到肺。與此同時，肺內富含氧氣的血液通過肺靜脈進入心臟。
The pulmonary veins empty into the left atrium, which contracts to push oxygen-rich blood through the mitral valve and into the left ventricle. The left ventricle contracts, pushing the blood through the aortic valve and into the aorta, which distributes blood to arteries throughout the body.The heart is supplied with blood through the coronary arteries, which branch off the aorta.
肺靜脈流入左心房，左心房收縮，將富含氧氣的血液通過二尖瓣推入左心室。接著，左心室收縮，將血液通過主動脈瓣推入主動脈，主動脈將血液運送到全身動脈。心臟的血液供應來自冠狀動脈。主動脈分出冠狀動脈。
