Section outline

  • Person with braided hair placing hands on chest, appearing contemplative.

    Where is your heart?
    ::你的心脏呢?

    Place your hand on your heart. Did you put your hand on the left side of your chest? Most people do, but the heart is actually located closer to the center of the chest.
    ::把你的手放在心脏上。你把你的手放在胸口的左侧了吗?大多数人都这样认为,但心脏实际上离胸口中心更近。

    The Heart
    ::心心

    What does the heart look like? How does it pump ? The heart is divided into four chambers ( Figure ), or spaces: the left and right atria , and the left and right ventricles . An atrium (singular for atria) is one of the two small, thin-walled chambers on the top of the heart where the blood first enters. A ventricle is one of the two muscular V-shaped chambers that pump blood out of the heart. You can remember they are called ventricles because they are shaped like a "V."
    ::心脏长什么样子? 它是如何抽动的? 心脏分为四个室室(图 ) 或四个空格: 左、 右、 左、 右、 心室。 心室( 单为阿提里亚 ) 是 心脏顶部的两个小薄壁室之一, 血液首先进入的。 心室是两个肌肉V型室之一, 将血液抽出心脏。 您可以记住, 它们被称为心室, 因为它们的形状像“ V ” 。

    The four chambers of the heart: left atrium, right atrium, left ventricle, right ventricle.

    The atria receive blood and the ventricles pump blood out of the heart.
    ::阿提雅接收血液 心血管抽出心脏的血液

    The atria receive the blood, and the ventricles pump the blood out of the heart. Each of the four chambers of the heart has a specific job.
    ::阿提雅接受血液,心血管抽出心脏的血液。心脏的4个细胞中,每个细胞都有特定的工作。

    • The right atrium receives oxygen-poor blood from the body.
      ::右中庭从身体中获取缺氧血液。
    • The right ventricle pumps oxygen-poor blood toward the lungs , where it receives oxygen.
      ::右心室泵 缺氧血液 进入肺部 获得氧气
    • The left atrium receives oxygen-rich blood from the lungs.
      ::左中子从肺部获得含氧血液。
    • The left ventricle pumps oxygen-rich blood out of the heart to the rest of the body.
      ::左心室泵 含氧丰富的血液 从心脏到身体其余部分

    Blood Flow Through the Heart
    ::血流满心

    Blood flows through the heart in two separate loops. You can think of them as a “left side loop” and a “right side loop.” The right side of the heart collects oxygen-poor blood from the body and pumps it into the lungs, where it releases carbon dioxide and picks up oxygen. (Recall that carbon dioxide is a waste product that must be removed. It is removed when we exhale.) The left side carries the oxygen-rich blood back from the lungs into the left side of the heart, which then pumps the oxygen-rich blood to the rest of the body. The blood delivers oxygen to the cells of the body, where it is needed for , and returns to the heart oxygen-poor.
    ::血液在两个不同的循环中流过心脏。你可以把它们视为“左侧循环”和“右侧循环 ” 。 心脏右侧从身体中收集缺氧血液,并将之注入肺部,释放二氧化碳并吸收氧气。 (注意二氧化碳是一种必须去除的废物产物。当我们呼气时,它会被去除。 )左侧将含氧血液从肺部带回心脏的左侧,然后将含氧血液泵到身体的其余部分。血液将氧气输送到身体的细胞中,并返回到缺氧的心脏。

    To move blood through the heart, the cardiac muscle needs to contract in an organized way. Blood first enters the atria ( Figure ). When the atria contract, blood is pushed into the ventricles. After the ventricles fill with blood, they contract, and blood is pushed out of the heart. The heart is mainly composed of cardiac muscle. These muscle cells contract in unison, causing the heart itself to contract and generating enough force to push the blood out.
    ::为了让血液穿透心脏,心脏肌肉需要以有组织的方式收缩。血液首先进入阿提里亚(图 ) 。 当阿提里亚( 图表 ) 收缩时, 血液被推入腹部。 当腹部充满血液后, 血液就会收缩, 血液会从心脏中抽出。 心脏主要由心脏肌肉肌肉组成。 这些肌肉细胞相互结合, 使心脏自己收缩, 产生足够的力量将血液挤出。

    So how is the blood kept from flowing back on itself? Valves ( Figure ) in the heart keep the blood flowing in one direction. The valves do this by opening and closing in one direction only. Blood only moves forward through the heart. The valves stop the blood from flowing backward. There are four valves of the heart.
    ::血液如何不自流回流呢? 心脏的阀门使血液向一个方向流动。 阀门只向一个方向打开和关闭, 血液只能从一个方向流过。 阀门阻止血液向后流。 心脏有四个阀门。

    • The two atrioventricular (AV) valves stop blood from moving from the ventricles to the atria.
      ::两个原生动阀门阻止血液从心室流到阿提雅。
    • The two semilunar (SL) valves are found in the arteries leaving the heart, and they prevent blood from flowing back from the arteries into the ventricles.
      ::在离开心脏的动脉中发现了两个半卢纳尔(SL)阀门,它们防止血液从动脉流回进入心室。

    Why does a heart beat? The “lub-dub” sound of the heartbeat is caused by the closing of the AV valves ("lub") and SL valves ("dub") after blood has passed through them.
    ::为什么心脏跳动?心跳声是AV阀门(“管子”)和SL阀门(“管子”)在血液穿透后关闭造成的。

    The heart showing blood flow and valve positions in each loop.

    Blood flows in only one direction in the heart. Blood enters the atria, which contract and push blood into the ventricles. The atria relax and the ventricles fill with blood. Finally, the ventricles contract and push blood around the body.
    ::血液流向心脏只有一个方向。 血液进入阿提里亚, 血液凝结并推入心室。 阿提利亚放松, 心室充斥着血液。 最后, 心室收缩, 将血液推入身体。

    Summary
    ::摘要

    • Blood enters the heart at the atria and then flows into the ventricles, which contract and push blood around the body.
      ::血液进入阿提里亚的心脏 然后流进心血管 血凝结并推动血液在身体周围
    • Valves in the heart keep the blood flowing in one direction.
      ::心脏的阀门让血液流向一个方向

    Explore More
    ::探索更多

    Use the resource below to answer the questions that follow.
    ::利用以下资源回答以下问题。

    • Working of the Heart at (1:36)
      ::心脏工作(1:36)
    1. How many chambers does a mammalian heart have? What are these chambers called?
      ::哺乳动物的心有多少个室?这些室叫什么来着?
    2. What are the smallest blood vessels in the body?
      ::身体中最小的血管是什么?
    3. What is the function of the circulatory system? What role does the heart play?
      ::循环系统的作用是什么?心脏的作用是什么?
    4. What passes from the cells into the capillaries? What passes into the cells from the capillaries?
      ::从细胞进入毛细管的通道是什么?从毛细管进入毛细管的通道是什么?从毛细管进入毛细管的通道是什么?

    Review
    ::回顾

    1. What are the ventricles?
      ::什么是心电图?
    2. Where does oxygen-poor blood first enter the heart?
      ::缺氧血液最先进入心脏的地方是哪里?
    3. What part of the heart pumps blood to the rest of the body?
      ::心脏的哪个部分 抽血给身体的其余部分?
    4. What is the purpose of the valves in the heart?
      ::心脏的阀门有什么用?