跟读练习: How the Heart Works (Animation) - 通过YouTube学习英语口语
C2
Our heart is an exciting organ.
162 句
如果句子过短或过长，请点击 Edit 进行调整。
1
Our heart is an exciting organ.
2
In this animation, we show the picturesque complexity and mechanical simplicity of the human heart.
3
The human heart lies well protected in the chest behind the ribs and sternum.
4
To the left and right are the lungs,
5
which absorb oxygen from the air we breathe.
6
The heart's task is to pump oxygen-poor blood through the lungs,
7
and then transport the oxygen-rich blood coming from the lungs into the rest of the body.
8
Let's take a look at the basic anatomy of our heart.
9
Blood enters and exits the heart through several large blood vessels.
10
The aorta has been considered an independent organ since February 2024.
11
The heart receives deoxygenated blood from the body through the inferior and superior vena cava.
12
It pumps this blood to the lungs with the help of the pulmonary artery.
13
The oxygenated blood from the lungs returns to the heart through the four pulmonary veins.
14
The heart then pumps this blood into the body by the aorta.
15
However, the heart itself is not supplied with blood with the help of the aorta.
16
The coronary arteries are embedded in the epicardial adipose tissue.
17
The heart supplies itself with oxygen and nutrients through these blood vessels.
18
There are two coronary arteries,
19
which supply the heart with oxygenated blood,
20
and the coronary sinus, through which the deoxygenated blood flows back into the heart.
21
A heart attack can occur when the coronary arteries become blocked,
22
narrowed or completely obstructed.
23
Blood can then no longer flow freely,
24
and oxygen and other nutrients cannot reach the heart muscles.
25
Let's first take a look at the internal structure of the human heart.
26
The coronary arteries just shown originate from the main artery,
27
also known as the aorta.
28
The openings of the arteries are located above or at the aortic valve,
29
which consists of three semilunar cusps.
30
The aortic valve is located at the end of the aorta.
31
The pulmonary valve is located at the end of the pulmonary artery.
32
Rarely, the valves have two or four cusps.
33
The heart has two other valves that consist of leaflets, or cusps too.
34
The mitral valve consists of two leaflets,
35
and the tricuspid valve has three of these leaflets.
36
When the tricuspid valve opens,
37
deoxygenated blood flows from the right atrium into the right ventricle.
38
The deoxygenated blood then flows through the opened pulmonary valve and then enters the lungs via the pulmonary artery.
39
The oxygenated blood from the lungs passes from the left atrium into the left ventricle through the mitral valve.
40
When the aortic valve opens,
41
the blood enters the body via the aorta.
42
The blood flow is controlled by the muscles of the heart.
43
The muscles contract and then relax again.
44
At that point, we show a simplified version of the pumping process.
45
Later, we will describe the process in more detail.
46
When the atria of the heart contract,
47
the atria's space becomes smaller.
48
The resulting pressure causes the blood to push the leaflets towards the ventricles.
49
This allows the blood to be pumped from the atria into the ventricles.
50
When the muscles of the atria contract,
51
the muscles of the ventricles relax.
52
And when the muscles of the ventricles contract,
53
the muscles of the atria relax.
54
The contraction of the ventricular muscles creates high blood pressure,
55
which pushes the leaflets towards the atrium.
56
However, the leaflets have thin,
57
fibrous cords that prevent the leaflets from being pushed into the atrium.
58
These cordae tendini are attached to papillary muscles that contract at the right moment.
59
The contraction of the right ventricular muscles causes the pulmonary valve to open.
60
This ultimately transports the blood to the lungs via the pulmonary artery.
61
Now let's take a look at the left atrium and the left ventricle.
62
The left ventricle's task is to pump oxygen-rich blood into the entire body.
63
To achieve this, the left atrium first pumps the blood,
64
coming from the lungs, into the left ventricle.
65
The muscles of the left ventricle then contract.
66
As in the right ventricle,
67
fibrous cords and muscles prevent the leaflets of the valve from being pushed into the atrium.
68
In the left ventricle, the muscle columns known as trabeculae carnii are particularly well-developed.
69
The resulting pressure opens the aortic valve and the blood is pumped through the entire body with the help of the aorta.
70
In this simplified illustration, we can clearly see how the blood is pumped through the body's blood vessels.
71
The left ventricle just shown supplies the entire body with oxygen-rich blood via the aorta.
72
Head, abdomen, arms and legs.
73
That way, nutrients, oxygen, immune cells,
74
waste products and much, much more are transported from one place to another.
75
The arteries transport the blood away from the heart and the veins transport the blood towards the heart.
76
The returning blood then reaches the right atrium of the heart via the inferior and superior vena cava.
77
And from there into the right ventricle.
78
The right ventricle then pumps the deoxygenated blood into the lungs with the help of the pulmonary artery.
79
Here the blood absorbs oxygen,
80
enters the left atrium and finally returns to the left ventricle and the aorta.
81
The anatomy and function of the lungs can be seen in the colourful animation on this channel.
82
As the pulmonary circulation is short but the systemic circulation is long,
83
the heart chambers require muscles of different strengths.
84
For this reason, the right ventricle has a much thinner muscle layer than the left ventricle.
85
The interventricular septum of the heart,
86
which separates the left and right ventricles,
87
also consists of strong muscles.
88
The atria have muscles too.
89
The fine parallel muscular ridges,
90
which scientists refer to as pectinate muscles,
91
can be found particularly in the right atrium.
92
In contrast, the left atrium with its atrial appendage has more of a smooth structure.
93
As we have previously only shown a simplified cardiac cycle,
94
we will now take a look at the actual process showing the right side of the heart.
95
The muscles of the atrium and ventricle are relaxed.
96
The tricuspid valve is open.
97
The pulmonary artery is closed through the pulmonary valve.
98
Contracting the atrial muscles initiates atrial systole,
99
which pushes blood from the atrium into the ventricle.
100
The atrial muscles then relax and the ventricular muscles contract.
101
The resulting pressure closes the tricuspid valve.
102
The ventricular muscles contract further and increase the pressure,
103
opening the pulmonary valve and forcing the blood into the pulmonary artery.
104
When the ventricular muscles relax again,
105
the pressure inside the ventricle drops.
106
This causes the pulmonary valve to close,
107
as the pressure in the pulmonary artery is higher than the pressure inside the ventricle.
108
The tricuspid valve opens, allowing blood to flow from the atrium into the ventricle.
109
Now the cycle begins again.
110
The cardiac cycle is generally divided into a diastole and a systole.
111
Diastole refers to the relaxed ventricle filled with blood.
112
Systole on the other hand refers to the contracted ventricle which ejects the blood.
113
Systole is divided into the contraction stage and the ejection stage.
114
is divided into an early filling stage and a late filling stage.
115
Electrical impulses are used to stimulate the heart muscles to contract.
116
The cells that generate these electrical impulses are known as the sinoatrial node.
117
Special muscle cells, shown here in green,
118
quickly transmit the electrical impulses to the muscle cells of the atria and the atrioventricular node.
119
There is only a narrow connection of muscle cells between the atria and the ventricles,
120
known as the bundle of his.
121
The atrioventricular node transmits the electrical impulses to the right and left bundles through through these special muscle cells.
122
Fast-conducting Purkinje fibers originate from the right and left bundles.
123
These Purkinje fibers then transmit the impulses very quickly to the heart muscle cells of the ventricles.
124
The sinoatrial node generates an electrical impulse which is transmitted through the internodal tracks to the atrial muscles and the atrioventricular node.
125
The AV node transmits the impulse with a time delay to the ventricles through the Purkinje fibers.
126
The sinoatrial node is capable of generating 60 to 80 electrical impulses per minute.
127
If the sinoatrial node fails,
128
the AV node can generate approximately 40 to 60 impulses per minute.
129
If the sinoatrial node and AV node fail,
130
the bundle of his can still produce 20 to 40 impulses.
131
For this reason, we speak of primary,
132
secondary and tertiary pacemaker cells.
133
Let us now illustrate the path of the impulses in the human heart.
134
The electrical impulses propagate in the atria and cause the muscles to contract,
135
thus pumping the blood into the ventricles.
136
The impulse is transmitted to the muscle cells of the ventricles via the AV node and the bundle of his.
137
This causes the ventricular muscles to contract and pump the blood into the pulmonary artery and the aorta.
138
The heart muscle cells have the special property of being able to transmit the electrical impulses to neighbouring muscle cells.
139
However, apart from the bundle of his,
140
there is no connection between the atrial muscles and the ventricular muscles.
141
For this reason, the atria and ventricles can contract at different times.
142
The contraction of the ventricles begins at the apex of the heart.
143
For this reason, the blood is literally squeezed out of the ventricles,
144
similar to a tube of toothpaste that is rolled in from the back to the front.
145
In medicine, electrical impulses can be used to check heart activity.
146
This is done with the help of an electrocardiogram.
147
The stimulation of the atria by the impulse of the sinoatrial node corresponds to the first wave.
148
The stimulation of the ventricles through the atrioventricular node is represented by three spikes.
149
The first wave is called the P wave,
150
and the three graphical deflections the QRS complex.
151
The last wave is the T wave,
152
which represents the recovery of the ventricles.
153
To allow the heart to change shape and size during contractions,
154
it is enclosed in the pericardium.
155
The pericardium consists of a semi-rigid outer layer of dense and loose connective tissue.
156
A smooth layer is attached to this outer layer.
157
Another smooth layer covers the heart.
158
In humans there is about 10-15ml of fluid between the two layers,
159
which serves as a lubricant.
160
This allows the heart to change its shape
161
and size in the pericardium without causing strong friction on the heart or other organs.
162
Many more animations about the human body are available on this channel and my website.
下载应用
AI 为你说出的每个句子打分
TRENDING
热门
背景与上下文
在这段视频中，讲述了人类心脏的工作原理，介绍了心脏的基本结构及其如何泵送血液。该动画生动展示了心脏的复杂性和机械简单性，使观众更加了解心脏在身体中的重要作用和功能。通过深入理解这些内容，英语学习者不仅可以提升他们的医学词汇，还能学到如何用英语进行日常交流，特别是在医疗和健康相关的话题上。
日常交流的五个常用短语
- 心脏的功能是什么？ (What is the function of the heart?)
- 氧气和营养如何到达心脏？ (How does oxygen and nutrients reach the heart?)
- 心脏病是如何发生的？ (How does a heart attack occur?)
- 如何保持心脏健康？ (How to keep the heart healthy?)
- 你能描述心脏的结构吗？ (Can you describe the structure of the heart?)
逐步影子跟读指南
要有效利用这段视频提升你的英语口语练习，我们可以采用shadow speech的技巧。以下是逐步的指南，帮助你轻松跟读：
- 初步观看：观看视频一遍，尽量理解内容，注意心脏的主要功能和结构。
- 分段学习：将视频分为几个小段逐个学习，确保每段理解透彻。
- 跟随原音：关闭字幕，尝试在听到每一句话时立即跟读，模仿发音和语调。
- 反复练习：选择自己觉得难度较大的句子，反复播放，并进行多次练习，以增强记忆。
- 应用所学：尝试在日常生活中使用这些新学的短语，通过与朋友或家人交流来增强口语能力。
通过这种方式，你能更好地掌握看YouTube学英语的技巧，并提高自己的英语水平，特别是在医疗领域的交流能力。运用shadowspeaks的方式，能让你的口语更加流利自信，逐步实现英语沟通的目标。
什么是跟读法？
跟读法 (Shadowing) 是一种有科学依据的语言学习技巧，最初开发用于专业口译员的培训，并由多语言者Alexander Arguelles博士普及。这个方法简单而强大：您在听英语母语原声的同时立即大声重复——就像是一个延迟1-2秒紧跟说话者的影子。与被动听力或语法练习不同，跟读法强迫您的大脑和口腔肌肉同时处理并模仿真实的讲话模式。研究表明它能显着提高发音准确性，语调，节奏，连读，听力理解和口语流利度——使其成为雅思口语备考和真实英语交流最有效的方法之一。