醫(yī)學(xué)英語(yǔ)是很多醫(yī)療工作者的難題，但不管怎樣，學(xué)習(xí)是不允許畏難的。下面就隨醫(yī)學(xué)教育網(wǎng)小編一起來(lái)看看今天這篇分享：Anatomy and Circulation of the Heart文本翻譯，相信會(huì)有所幫助！

Your heart is an amazing organ. It continuously pumps oxygen and nutrient-rich blood throughout your body to sustain life. This fist-sized powerhouse beats (expands and contracts) 100,000 times per day, pumping five or six quarts of blood each minute, or about 2,000 gallons per day.

心臟是令人驚奇的器官，它不斷地泵出富含氧氣和營(yíng)養(yǎng)物質(zhì)的血液到達(dá)人體各部分以維持生命。心臟有拳頭大小，通過(guò)舒張收縮而跳動(dòng)，每天跳動(dòng)10萬(wàn)次，每分鐘泵出5-6夸脫血液，大約一天2千加侖。

How Does Blood Travel Through the Heart?

As the heart beats, it pumps blood through a system of blood vessels, called the circulatory system. The vessels are elastic tubes that carry blood to every part of the body.

Blood is essential. In addition to carrying fresh oxygen from the lungs and nutrients to your body's tissues, it also takes the body's waste products, including carbon dioxide, away from the tissues. This is necessary to sustain life and promote the health of all the body's tissues.

There are three main types of blood vessels:

Arteries. They begin with the aorta, the large artery leaving the heart. Arteries carry oxygen-rich blood away from the heart to all of the body's tissues. They branch several times, becoming smaller and smaller as they carry blood farther from the heart.

Capillaries. These are small, thin blood vessels that connect the arteries and the veins. Their thin walls allow oxygen, nutrients, carbon dioxide, and other waste products to pass to and from our organ's cells.

Veins. These are blood vessels that take blood back to the heart; this blood lacks oxygen (oxygen-poor) and is rich in waste products that are to be excreted or removed from the body. Veins become larger and larger as they get closer to the heart. The superior vena cava is the large vein that brings blood from the head and arms to the heart, and the inferior vena cava brings blood from the abdomen and legs into the heart.

This vast system of blood vessels -- arteries, veins, and capillaries -- is over 60,000 miles long. That's long enough to go around the world more than twice!

Blood flows continuously through your body's blood vessels. Your heart is the pump that makes it all possible.

血液是如何流經(jīng)心臟的呢？

心臟通過(guò)跳動(dòng)將血液泵入血管，心臟和血管統(tǒng)稱(chēng)為循環(huán)系統(tǒng)。運(yùn)輸血液到達(dá)機(jī)體每個(gè)部分的血管均具有彈性。

血液是人體必需的。除了將來(lái)自肺部的新鮮氧氣、營(yíng)養(yǎng)物質(zhì)運(yùn)輸至人體的各個(gè)組織，又將各組織代謝的廢物如二氧化碳等運(yùn)輸至排泄器官，這個(gè)過(guò)程對(duì)維持基本的生命活動(dòng)以及促進(jìn)機(jī)體健康是必要的。

血管主要分為三種類(lèi)型：

動(dòng)脈。起于與心臟相連的大動(dòng)脈——主動(dòng)脈，運(yùn)輸富含氧氣的血液離開(kāi)心臟至機(jī)體的各個(gè)組織。隨著血液的運(yùn)輸，動(dòng)脈逐級(jí)分支，越分越細(xì)。

毛細(xì)血管。連接動(dòng)靜脈，管壁薄，管腔小。毛細(xì)血管和各器官組織通過(guò)血管壁進(jìn)行氧氣、營(yíng)養(yǎng)物質(zhì)、二氧化碳和其他代謝產(chǎn)物的物質(zhì)交換。

靜脈。將含有代謝產(chǎn)物和含氧量少的血液運(yùn)回心臟，進(jìn)而排出體外。靜脈離心臟越近，管腔越粗。血液通過(guò)上腔靜脈從頭、臂部返回到心臟以及通過(guò)下腔靜脈將血液從腹部、腿部返回至心臟。

血管系統(tǒng)包括動(dòng)脈、靜脈和毛細(xì)血管，長(zhǎng)達(dá)6萬(wàn)多英里，足以環(huán)繞地球兩圈。心臟不斷泵血，使血流持續(xù)經(jīng)血管流至機(jī)體各部分。

Where Is Your Heart and What Does It Look Like?

The heart is located under the rib cage, to the left of your breastbone (sternum) and between your lungs.

Looking at the outside of the heart, you can see that the heart is made of muscle. The strong muscular walls contract (squeeze), pumping blood to the arteries. The major blood vessels connected to your heart are the aorta, the superior vena cava, the inferior vena cava, the pulmonary artery (which takes oxygen-poor blood from the heart to the lungs where it is oxygenated), the pulmonary veins (which bring oxygen-rich blood from the lungs to the heart), and the coronary arteries (which supply blood to the heart muscle).

On the inside, the heart is a four-chambered, hollow organ. It is divided into the left and right side by a wall called the septum. The right and left sides of the heart are further divided into two top chambers called the atria, which receive blood from the veins, and two bottom chambers called ventricles, which pump blood into the arteries.

The atria and ventricles work together, contracting and relaxing to pump blood out of the heart. As blood leaves each chamber of the heart, it passes through a valve. There are four heart valves within the heart:

Mitral valve

Tricuspid valve

Aortic valve

Pulmonic valve (also called pulmonary valve)

The tricuspid and mitral valves lie between the atria and ventricles. The aortic and pulmonic valves lie between the ventricles and the major blood vessels leaving the heart.

The heart valves work the same way as one-way valves in the plumbing of your home. They prevent blood from flowing in the wrong direction.

Each valve has a set of flaps, called leaflets or cusps. The mitral valve has two leaflets; the others have three. The leaflets are attached to and supported by a ring of tough, fibrous tissue called the annulus. The annulus helps to maintain the proper shape of the valve.

The leaflets of the mitral and tricuspid valves are also supported by tough, fibrous strings called chordae tendineae. These are similar to the strings supporting a parachute. They extend from the valve leaflets to small muscles, called papillary muscles, which are part of the inside walls of the ventricles.

心臟的位置和外形

心臟位于肋骨下，胸骨左側(cè)，兩肺之間。

從外形上，心臟由心肌組成，心肌強(qiáng)有力收縮泵出血液至動(dòng)脈。與心臟連接的血管主要是主動(dòng)脈、上腔靜脈、下腔靜脈、肺動(dòng)脈、肺靜脈、冠狀動(dòng)脈。含氧量少的血液由心臟經(jīng)肺動(dòng)脈運(yùn)輸至肺，而肺靜脈將富含氧氣的血液由肺運(yùn)至心臟。冠狀動(dòng)脈為心肌提供血液。

觀其內(nèi)部，心臟是由四個(gè)空腔構(gòu)成的器官，由間隔分為左右兩部分，心臟的左右兩部分又各分為兩個(gè)腔，即心房、心室。心房位于上面，接收來(lái)自靜脈的血液，心室位于下部，將血液泵出至動(dòng)脈。

心房和心室通過(guò)收縮舒張協(xié)同工作共同泵出血液。血液離開(kāi)心腔時(shí)會(huì)通過(guò)瓣膜。心臟有四個(gè)心瓣膜：二尖瓣、三尖瓣、動(dòng)脈瓣、肺動(dòng)脈瓣。

三尖瓣、二尖瓣位于房室之間，主動(dòng)脈瓣、肺動(dòng)脈瓣位于心室和運(yùn)輸血液離開(kāi)心臟的主要血管之間。

心瓣膜保證血液沿一個(gè)方向流動(dòng)，從而避免血液反流。

每個(gè)瓣膜都有一套瓣葉。二尖瓣有兩個(gè)瓣葉，其余瓣有三個(gè)瓣葉。這些瓣葉都附著在硬的纖維組織上，即瓣環(huán)，以維持瓣膜的形狀。

二尖瓣、三尖瓣的瓣葉也附著在硬的纖維索上，即腱索。這就像降落傘由繩索支持。腱索連接瓣葉尖和心室內(nèi)壁上的乳頭肌。

How Does Blood Flow Through the Heart?

The right and left sides of the heart work together. The pattern described below is repeated over and over, causing blood to flow continuously to the heart, lungs, and body.

Right side

Blood enters the heart through two large veins, the inferior and superior vena cava, emptying oxygen-poor blood from the body into the right atrium.

As the atrium contracts, blood flows from your right atrium into your right ventricle through the open tricuspid valve.

When the ventricle is full, the tricuspid valve shuts. This prevents blood from flowing backward into the atria while the ventricle contracts.

As the ventricle contracts, blood leaves the heart through the pulmonic valve, into the pulmonary artery and to the lungs where it is oxygenated.

Left side

The pulmonary vein empties oxygen-rich blood from the lungs into the left atrium.

As the atrium contracts, blood flows from your left atrium into your left ventricle through the open mitral valve.

When the ventricle is full, the mitral valve shuts. This prevents blood from flowing backward into the atrium while the ventricle contracts.

As the ventricle contracts, blood leaves the heart through the aortic valve, into the aorta and to the body.

血液如何流經(jīng)心臟？

心臟左右兩部分共同工作，以一種方式一遍遍重復(fù)，使血液流至肺、心臟和機(jī)體其余各部分。

心臟的右邊部分

血液通過(guò)兩個(gè)大靜脈，即上下腔靜脈流至血液，將乏氧血液從機(jī)體各部分運(yùn)至右心房。

心房收縮，三尖瓣處于開(kāi)放狀態(tài)，血液從右心房流到右心室。

心室血液充盈完畢，三尖瓣關(guān)閉，阻止右心室收縮時(shí)右心室的血液反流至右心房。

右心室收縮，肺動(dòng)脈瓣處于開(kāi)放狀態(tài)，血液經(jīng)肺動(dòng)脈從右心室到達(dá)富含氧的肺。

左邊部分

肺靜脈將富含氧氣的血液從肺運(yùn)至左心房。

左心房收縮，二尖瓣處于開(kāi)放狀態(tài)，血液從左心房流至左心室。

左心室充盈完畢，二尖瓣關(guān)閉。阻止左心室收縮時(shí)，左心室的血液反流至左心房。

左心室收縮，主動(dòng)脈瓣處于開(kāi)放狀態(tài)，血液從左心室流至主動(dòng)脈再至機(jī)體各器官。

How Does Blood Flow Through Your Lungs?

Once blood travels through the pulmonic valve, it enters your lungs. This is called the pulmonary circulation. From your pulmonic valve, blood travels to the pulmonary artery to tiny capillary vessels in the lungs.

Here, oxygen travels from the tiny air sacs in the lungs, through the walls of the capillaries, into the blood. At the same time, carbon dioxide, a waste product of metabolism, passes from the blood into the air sacs. Carbon dioxide leaves the body when you exhale. Once the blood is purified and oxygenated, it travels back to the left atrium through the pulmonary veins.

血液怎么流經(jīng)肺呢？

肺循環(huán)的過(guò)程是血液通過(guò)肺動(dòng)脈瓣，進(jìn)入肺動(dòng)脈，再到肺毛細(xì)血管，氧氣通過(guò)肺毛細(xì)血管壁從肺泡進(jìn)入血液，同時(shí)，二氧化碳、代謝產(chǎn)物從血液進(jìn)入到肺泡。二氧化碳隨著呼氣離開(kāi)體內(nèi)。來(lái)自肺動(dòng)脈的血液經(jīng)凈化和氧化后，通過(guò)肺靜脈流至左心房。

What Are the Coronary Arteries?

Like all organs, your heart is made of tissue that requires a supply of oxygen and nutrients. Although its chambers are full of blood, the heart receives no nourishment from this blood. The heart receives its own supply of blood from a network of arteries, called the coronary arteries.

Two major coronary arteries branch off from the aorta near the point where the aorta and the left ventricle meet:

Right coronary artery supplies the right atrium and right ventricle with blood. It usually branches into the posterior descending artery, which supplies the bottom portion of the left ventricle and back of the septum with blood.

Left main coronary artery branches into the circumflex artery and the left anterior descending artery. The circumflex artery supplies blood to the left atrium, side, and back of the left ventricle, and the left anterior descending artery supplies the front and bottom of the left ventricle and the front of the septum with blood.

These arteries and their branches supply all parts of the heart muscle with blood.

When the coronary arteries narrow to the point that blood flow to the heart muscle is limited (coronary artery disease), a network of tiny blood vessels in the heart that aren't usually open called collateral vessels may enlarge and become active. This allows blood to flow around the blocked artery to the heart muscle, protecting the heart tissue from injury.

什么是冠狀動(dòng)脈？

心臟和其他器官一樣，需要氧氣和營(yíng)養(yǎng)物質(zhì)的供給。即使心腔充滿(mǎn)血液，心臟也沒(méi)有從中去獲取營(yíng)養(yǎng)，而是通過(guò)網(wǎng)狀的動(dòng)脈即冠狀動(dòng)脈獲取。

靠近主動(dòng)脈和左心室交界處的主動(dòng)脈竇發(fā)出左右冠狀動(dòng)脈：

右冠狀動(dòng)脈為右心房、右心室提供血液。它通常發(fā)出冠狀動(dòng)脈后降支供應(yīng)左心室的底部和室間隔的后部。

左冠狀動(dòng)脈主干發(fā)出旋支和左前降支冠狀動(dòng)脈。旋支供應(yīng)左心房、左心室的外緣和背部。左前降支供應(yīng)左心室的前部和底部、室間隔的前部。

這些動(dòng)脈及分支為心肌提供血液。當(dāng)冠狀動(dòng)脈狹窄到一定程度，提供給心肌的血流被限制（冠心病），不經(jīng)常開(kāi)放的微小網(wǎng)狀血管，即側(cè)支血管，此時(shí)可能會(huì)擴(kuò)張，變得活躍，在被堵塞的血管旁建立有效的循環(huán)，避免心肌損傷。

How Does the Heart Beat?

The atria and ventricles work together, alternately contracting and relaxing to make the heart beat and pump blood. The electrical system of your heart is the power source that makes this possible.

Your heartbeat is triggered by electrical impulses that travel down a special pathway through your heart.

The impulse starts in a small bundle of specialized cells called the SA node (sinoatrial node), located in the right atrium. This node is known as the heart's natural pacemaker. The electrical activity spreads through the walls of the atria and causes them to contract.

A cluster of cells in the center of the heart between the atria and ventricles, the AV node (atrioventricular node) is like a gate that slows the electrical signal before it enters the ventricles. This delay gives the atria time to contract before the ventricles do.

The His-Purkinje network is a pathway of fibers that sends the impulse to the muscular walls of the ventricles, causing them to contract.

At rest, a normal heart beats around 50 to 99 times a minute. Exercise, emotions, fever, and some medications can cause your heart to beat faster, sometimes to well over 100 beats per minute.

心臟如何跳動(dòng)的呢？

心跳由電沖動(dòng)沿著心臟特殊路徑傳導(dǎo)而產(chǎn)生。

心房、心室通過(guò)電活動(dòng)產(chǎn)生收縮、舒張進(jìn)而使心臟跳動(dòng)和泵血。

電沖動(dòng)起自位于右心房的竇房結(jié)（心臟的起搏器），沿著心房壁傳導(dǎo)，引起心房收縮。

房室結(jié)，位于心臟中心，心房、心室之間的一群細(xì)胞，使電信號(hào)進(jìn)入心室之前傳導(dǎo)速度減慢，保證心房收縮后再開(kāi)始心室收縮。

希氏束將電沖動(dòng)傳至心室引起心室收縮。

安靜時(shí)，正常心跳50-99次/分。在運(yùn)動(dòng)、情緒波動(dòng)、發(fā)熱和服用一些藥物時(shí)可引起心跳加快，甚至達(dá)到100次/分以上。

以上就是我為大家整理的Anatomy and Circulation of the Heart文本翻譯，還請(qǐng)大家多多關(guān)注醫(yī)學(xué)教育網(wǎng)，我們會(huì)隨時(shí)更新更多更好的有關(guān)醫(yī)學(xué)知識(shí)、醫(yī)療招聘及考試輔導(dǎo)等相關(guān)信息。敬請(qǐng)期待！