你的心中

The human heart is one of the hardest-working organs in the body.

On average, it beats around 75 times a minute. As the heart beats, it provides pressure so blood can flow to deliver oxygen and important nutrients to tissue all over your body through an extensive network of arteries, and it has return blood flow through a network of veins.

In fact, the heart steadily pumps an average of 2,000 gallons of blood through the body each day.

你的心中is located underneath your sternum and ribcage, and between your two lungs.

The heart’s four chambers function as a double-sided pump, with an upper and continuous lower chamber on each side of the heart.

The heart’s four chambers are:

  • Right atrium.This chamber receives venous oxygen-depleted blood that has already circulated around through the body, not including the lungs, and pumps it into the right ventricle.
  • 右心室。右心室将血液从右心房泵送到肺动脉。肺动脉将脱氧的血液传递到肺部，在那里捡起氧气以换取二氧化碳。
  • Left atrium.该腔室从肺的肺静脉中接收含氧血液，并将其泵送到左心室。
  • Left ventricle.With the thickest muscle mass of all the chambers, the left ventricle is the hardest pumping part of the heart, as it pumps blood that flows to the heart and rest of the body other than the lungs.

心脏的两个心房都位于心脏顶部。他们有责任从您的静脉中接受血液。

心脏的两个心室位于心脏的底部。他们负责将血液泵入您的动脉。

您的心房和心室收缩，使您的心脏跳动并通过每个房间抽血。每次节拍之前，您的心室充满了血液，收缩将血液推入下一个房间。收缩是由从鼻窦节点开始的电脉冲触发的，该脉冲（也称为Sinoatrial节点（SA节点））位于右心房组织中。

The pulses then travel through your heart to the atrioventricular node, also called the AV node, located near the center of the heart between the atria and the ventricles. These electrical impulses keep your blood flowing in proper rhythm.

The heart has four valves, one each at the downstream end of each chamber, so that, under normal conditions, blood can’t flow backward, and the chambers can fill with blood and pump blood forward properly. These valves can sometimes be repaired or replaced if they become damaged.

心脏的阀门are:

  • Tricuspid (right AV) valve.该阀打开以使血液从右心庭流向右心室。
  • 肺动脉瓣。该瓣膜可以使血液从左心室流入肺动脉流向肺部，从而使心脏和身体的其余部分可以接受更多的氧气。
  • 二尖瓣（左AV）阀。该阀打开，使血液从左心房流向左心室。
  • 主动脉瓣。This valve opens to let blood leave the left ventricle so that the blood can flow to the heart and the rest of body, save the lungs.

正常工作时，除了肺部以外，从器官中恢复了脱氧的血液，通过两种称为静脉腔的主要静脉进入心脏，心脏通过冠状动脉窦将其静脉血恢复到自身。

从这些静脉结构中，血液进入右心庭，并通过三尖瓣进入右心室。然后，血液将肺动脉瓣流入肺动脉躯干，然后通过左右肺动脉向肺部传播，在空气交换过程中，血液会在那里接受氧气。

在从肺部返回的路上，充氧的血液通过左右肺静脉进入心脏的左心房。然后，血液流过二尖瓣的左心室，即心脏的动力室。

The blood travels out the left ventricle through the aortic valve, and into the aorta, extending upward from the heart. From there, the blood moves through a maze of arteries to get to every cell in the body other than the lungs.

The structure of the heart’s blood supply is called the coronary circulatory system. The word “coronary” comes from the Latin word meaning “of a crown.” The arteries that fuel the heart’s muscle encircle the heart like a crown.

冠心病，也称为冠状动脉疾病，通常会在含有胆固醇和脂肪斑块的钙收集并伤害心脏肌肉的动脉时发育。如果这些斑块中的一部分破裂，它可能会突然堵塞其中一艘血管并导致心肌开始死亡（myocardial infarction），因为它是氧气和养分的饥饿感。如果在心脏的一个动脉中形成血凝块，这也会发生这种情况，这可能在斑块破裂后立即发生。