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Are You Sure Your Heart’s In The Right Place?
On today’s Moment of Science, we’re sure your heart’s in the right place. But where is it exactly?!? CPR classes show how to press on the sternum, in the center of the chest, to stimulate the heart. But then again, hearing the heartbeat is easier on the left.
What Gives?
Anatomically speaking, the heart is pretty much centered in the chest cavity, although it is tilted to the left, and takes a bit more space from the neighboring left lung than the right.
To understand why the heartbeat’s easier to hear on the left side, we need to know about the four chambers of the heart.
Top Of The Heart
The atria are the two small chambers at the top of the heart. The two ventricles are the larger, more muscular chambers on the bottom. Because the atria simply pump blood down to the ventricles, they don’t need to be that muscular.
The right ventricle needs to be more bulky, because it pumps blood out to the lungs to get oxygen. But the left ventricle has the most difficult task–pumping blood to the rest of the body–so it’s the most muscular chamber of the heart. It’s also closest to the chest wall, while the atria are farther back, tucked under the lungs.
Work That Heart
That means that the left ventricle, the hardest-working chamber of the heart, is not only farthest to the left but also closest to the chest wall. And that’s why it’s so easy to hear your heartbeat on the left, even though the heart is nearly centered in the chest.
你能確定自己的心臟是在正確的位置上么？
在今天的《科學(xué)一刻》里，我們確信你的心臟在正確的位置上。可是具體是在哪里呢？心臟復(fù)蘇課程向我們介紹了如何按壓位于胸部中心的胸骨來(lái)復(fù)蘇心臟。然而，心跳聲在胸部偏左更容易聽(tīng)到。
心臟是什么樣的？
從解剖學(xué)上說(shuō)，心臟幾乎是在胸腔正中的位置的，不過(guò)稍微向左傾斜，與右肺相比，它占據(jù)了左肺更多的位置。
為了理解為什么更容易從從左邊聽(tīng)到心跳聲，我們需要對(duì)心臟的四個(gè)腔有所了解。
心臟上部
心房是指位于心臟上部的兩個(gè)小腔。心室是指心臟下部更大，肌肉更發(fā)達(dá)的兩個(gè)腔。因?yàn)樾姆恐恍鑼⒀簤旱叫氖壹纯桑约∪獠恍枰敲窗l(fā)達(dá)。
右心室體積要更龐大，因?yàn)樾枰ㄟ^(guò)它將血液泵入肺中獲取氧氣。而左心室的任務(wù)重——將血液泵入身體其他部分——因此也是心臟中肌肉發(fā)達(dá)的肌室。左心室也是離胸壁近的部分。而心房則離胸壁較遠(yuǎn)，藏在肺里。
讓心臟動(dòng)起來(lái)
也就是說(shuō)左心室，這個(gè)在心臟中工作重的肌室，不僅位于左面，而且離胸壁近。這就是盡管心臟基本是在胸部正中，你卻能很容易的從左面聽(tīng)到心跳聲的原因。
Are You Sure Your Heart’s In The Right Place?
On today’s Moment of Science, we’re sure your heart’s in the right place. But where is it exactly?!? CPR classes show how to press on the sternum, in the center of the chest, to stimulate the heart. But then again, hearing the heartbeat is easier on the left.
What Gives?
Anatomically speaking, the heart is pretty much centered in the chest cavity, although it is tilted to the left, and takes a bit more space from the neighboring left lung than the right.
To understand why the heartbeat’s easier to hear on the left side, we need to know about the four chambers of the heart.
Top Of The Heart
The atria are the two small chambers at the top of the heart. The two ventricles are the larger, more muscular chambers on the bottom. Because the atria simply pump blood down to the ventricles, they don’t need to be that muscular.
The right ventricle needs to be more bulky, because it pumps blood out to the lungs to get oxygen. But the left ventricle has the most difficult task–pumping blood to the rest of the body–so it’s the most muscular chamber of the heart. It’s also closest to the chest wall, while the atria are farther back, tucked under the lungs.
Work That Heart
That means that the left ventricle, the hardest-working chamber of the heart, is not only farthest to the left but also closest to the chest wall. And that’s why it’s so easy to hear your heartbeat on the left, even though the heart is nearly centered in the chest.
你能確定自己的心臟是在正確的位置上么？
在今天的《科學(xué)一刻》里，我們確信你的心臟在正確的位置上。可是具體是在哪里呢？心臟復(fù)蘇課程向我們介紹了如何按壓位于胸部中心的胸骨來(lái)復(fù)蘇心臟。然而，心跳聲在胸部偏左更容易聽(tīng)到。
心臟是什么樣的？
從解剖學(xué)上說(shuō)，心臟幾乎是在胸腔正中的位置的，不過(guò)稍微向左傾斜，與右肺相比，它占據(jù)了左肺更多的位置。
為了理解為什么更容易從從左邊聽(tīng)到心跳聲，我們需要對(duì)心臟的四個(gè)腔有所了解。
心臟上部
心房是指位于心臟上部的兩個(gè)小腔。心室是指心臟下部更大，肌肉更發(fā)達(dá)的兩個(gè)腔。因?yàn)樾姆恐恍鑼⒀簤旱叫氖壹纯桑约∪獠恍枰敲窗l(fā)達(dá)。
右心室體積要更龐大，因?yàn)樾枰ㄟ^(guò)它將血液泵入肺中獲取氧氣。而左心室的任務(wù)重——將血液泵入身體其他部分——因此也是心臟中肌肉發(fā)達(dá)的肌室。左心室也是離胸壁近的部分。而心房則離胸壁較遠(yuǎn)，藏在肺里。
讓心臟動(dòng)起來(lái)
也就是說(shuō)左心室，這個(gè)在心臟中工作重的肌室，不僅位于左面，而且離胸壁近。這就是盡管心臟基本是在胸部正中，你卻能很容易的從左面聽(tīng)到心跳聲的原因。