1 Why Do I Bleed

WHY DO I BLEED? WHY DO I?

我为什么流血？为什么呢？

Do You Need a Bandage? Have you ever cut your finger, had a bloody nose, or needed a bandage for your knee? What is that red stuff in your body, and what does it do? When you cut or scratch your skin, the red stuff that comes out is your blood. Blood is very important—and it's supposed to stay inside you! But what exactly is blood? Where does it come from?

你需要绷带吗？你有没有割破手指，流鼻血，或者需要用绷带包扎膝盖？ 你身体里的红色东西是什么，它有什么作用？ 当你割伤或抓伤你的皮肤时，流出来的红色东西是你的血。 血液是非常重要的——它应该留在你体内！但血到底是什么？ 它从何而来？

What Is Blood For? All humans and most animals have blood inside their bodies. We need it to live. Blood has a lot of really important jobs to do. REALLY GOOD STUFF Blood travels all through our bodies. It carries useful things, such as oxygen, to the body parts that need them. Blood also heals cuts and helps protect us from illnesses. But how? Oxygen

血有什么用？所有人和大多数动物的体内都有血液。 我们需要它来生存。血液有很多非常重要的作用。 血液在我们的身体里流动。 它携带有用的东西，比如氧气，到身体需要它们的部位。 血液还能治愈伤口，保护我们免受疾病的侵害。 但如何?氧气

Red or White? What is in your blood? Blood is made up of tiny parts called cells. Red blood cells carry oxygen around the body. White blood cells attack and destroy diseases and germs. Blood also contains material that helps heal cuts. The material clumps together to stop the blood from flowing out. A liquid in blood carries things such as nutrients around the body.

红葡萄酒还是白葡萄酒？你的血液里有什么？ 血液是由称为细胞的微小部分组成的。 红细胞携带氧气到全身各处。 白细胞攻击并消灭疾病和细菌。 血液中也含有有助于伤口愈合的物质。 这些物质聚集在一起，阻止血液流出。 血液中的液体携带诸如营养物质等物质到全身各处。

The Heart Pumps Blood Your heart is an organ. An organ is a body part that does a job. The heart's job is to pump your blood around your body. The left side of your heart is called the left ventricle. It sends blood full of oxygen from the lungs to the rest of the body. Left Ventricle The right side of the heart is called the right ventricle. It sends the used blood back to the lungs to be filled with oxygen again. Right Ventricle

心脏泵血心脏是一个器官。 器官是身体中起作用的部分。 心脏的功能是将血液输送到全身。 心脏的左侧叫做左心室。 它将充满氧气的血液从肺部输送到身体的其他部位。 左心室心脏的右侧称为右心室。 它将用过的血液送回肺部再次充满氧气。 右心室

Feel the Beat As your heart pumps the blood, it beats in a steady rhythm. If you listen to someone's chest, you will hear a bump-bump, bump-bump sound. This is called a heartbeat. BUMP BUMP BUMP BUMP A heart beats over 2.5 billion times in a person's lifetime!

当你的心脏泵出血液时，它以稳定的节奏跳动。 如果你听某人的胸部，你会听到砰砰砰的声音。 这就是心跳。 人的一生中，心脏跳动超过25亿次！