28 The Human Body-High

The Human Body Written by Kira Freed

《人体》作者:基拉·弗里德

Introduction Your body is like a busy city. A city has homes, stores, streets, a power station, waste management, and much more. Like a city, your body has different systems that work together to keep you alive. All the systems are working all the time, and they all need to remain healthy to do their jobs. Do You Know? Check your knowledge before reading this book. What do you know about each of the systems in your body? skeletal system muscular system nervous system respiratory system circulatory system digestive system excretory system reproductive system endocrine system immune system

你的身体就像一座繁忙的城市。 城市有住宅、商店、街道、发电站、废物处理设施等等。 就像一座城市一样，你的身体有不同的系统共同工作来维持你的生命。 所有的系统都一直在工作，它们都需要保持健康来完成它们的工作。 你知道吗?在阅读这本书之前检查一下你的知识。 你对身体的各个系统了解多少? 骨骼系统肌肉系统神经系统呼吸系统循环系统消化系统排泄系统生殖系统内分泌系统免疫系统

Every minute of your life, your heart is pumping blood throughout your body. Messages are traveling to and from your brain, and your lungs are carrying life-giving oxygen to cells. Your body is killing harmful germs, controlling your temperature, and removing waste products. It is also performing thousands more tasks— even while you are sleeping! In this book, you will learn about seven of these important body systems. As you read, think about all the tasks each body system is performing to keep you alive and healthy.

生命中的每一分钟，你的心脏都在向全身输送血液。 信息在你的大脑之间来回传递，你的肺将生命所需的氧气输送给细胞。 你的身体正在杀死有害细菌，控制体温，清除废物。 它还在执行数以千计的任务——甚至在你睡觉的时候!在这本书中，你将了解这些重要的身体系统中的七个。 当你阅读时，想想每个身体系统为保持生命和健康所执行的所有任务。

The Skeletal System The bones of your skeletal system support the rest of your body. Like the steel beams inside the walls of buildings, they provide support for all the other systems. Without bones, your body would collapse into a mushy blob! Bones also protect organs and play an important role in your body's movement. Your spine, the main support, is a long column of twenty-six bones. Your skull, a bony case at the top of the column, protects your brain from injury. Some of the bones of your spine have ribs attached to them. Your ribs wrap around your chest, protecting your heart and lungs.

骨骼系统骨骼系统的骨骼支撑着身体的其他部分。 就像建筑物墙壁内的钢梁一样，它们为所有其他系统提供支撑。 没有骨头，你的身体会变成一团糊状!骨骼还保护器官，在身体运动中发挥重要作用。 你的脊椎是主要的支撑，是由26块骨头组成的一根长柱。 你的头骨是柱体顶部的一个骨壳，保护你的大脑不受伤害。 你脊椎的一些骨头上有肋骨。 你的肋骨环绕着你的胸部，保护你的心脏和肺。

Your pelvis helps to protect the organs of your abdomen. Muscles attached to bones in your arms and legs help you move. Long, strong bones provide support for your arms and legs. Your hands, wrists, feet, and ankles contain many smaller bones. Each of the 206 bones in your body has a special job. The place where two bones meet is called a joint. Some joints bend or rotate, allowing you to move in many ways. Did you realize that your bones are alive? Bones are made of living cells. This is why bones grow. Spongy material in the center of bones, called bone marrow, makes new blood cells. Do You Know? Can you guess where the smallest bones in your body are? They're in your middle ears! Three tiny bones carry vibrations from your eardrums to your inner ears.

骨盆有助于保护腹部器官。 手臂和腿部骨骼上的肌肉帮助你移动。 长而强壮的骨头为你的胳膊和腿提供支撑。 你的手、手腕、脚和脚踝含有许多较小的骨头。 人体206块骨头中的每一块都有特殊的功能。 两块骨头相接的地方叫做关节。 一些关节可以弯曲或旋转，让你以多种方式移动。 你意识到你的骨头是活的吗? 骨头是由活细胞构成的。 这就是骨头生长的原因。骨骼中心的海绵物质，称为骨髓，产生新的血细胞。 你知道吗?你能猜到你身体里最小的骨头在哪里吗? 它们在你的中耳里!三个小骨头将振动从耳膜传递到内耳。

The Muscular System The muscular system, along with the skeletal system, allows your body to move. Unlike other body tissues, your muscles can contract (become shorter and tighter) or relax (become longer and looser). Muscles use the energy from the food you eat to do this work. The muscles that bend your joints never push— they only pull, which is why they must work in pairs. When one contracts, its partner relaxes. Then they switch jobs. Your body has three types of muscles— skeletal, smooth, and cardiac. Wowser! Your body has more than 650 muscles! Almost half your weight is muscles.

肌肉系统肌肉系统和骨骼系统使你的身体能够运动。 与其他身体组织不同，你的肌肉可以收缩(变短变紧)或放松(变长变松)。 肌肉利用你所吃的食物中的能量来完成这项工作。 弯曲关节的肌肉从来不会推，它们只会拉，这就是为什么它们必须成双成对地工作。 当一方收缩时，另一方放松。 然后他们换工作。你的身体有三种类型的肌肉——骨骼肌肉、光滑肌肉和心脏肌肉。 老古板!你的身体有650多块肌肉!你的体重几乎一半是肌肉。