26 The Human Body-Low

The Human Body Written by Kira Freed

《人体》作者:基拉·弗里德

Introduction Your body has many systems that work together to keep you alive. The systems are working all the time. They all need to stay healthy to do their jobs. Do You Know? See what you know before you read this book. What do you know about each of these body systems? skeletal system muscular system nervous system respiratory system circulatory system digestive system excretory system reproductive system endocrine system immune system

你的身体有许多系统共同工作来维持你的生命。 系统一直在工作。 他们都需要保持健康才能工作。 你知道吗?在你读这本书之前看看你知道些什么。 你对这些身体系统了解多少? 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 pumps blood. Messages move to and from your brain. Your lungs carry oxygen to cells. Your body kills bad germs and gets rid of waste products. It also does many more jobs—even while you sleep! In this book, you will learn about seven important body systems. As you read, think about all the jobs each body system does to keep you alive and healthy.

你生命中的每一分钟，你的心脏都在输送血液。 信息在你的大脑中来回移动。 你的肺将氧气输送到细胞。 你的身体会杀死有害细菌并清除废物。 它还能做更多的工作——甚至在你睡觉的时候!在这本书中，你将了解七个重要的身体系统。 当你阅读时，想想每个身体系统为保持你的生命和健康所做的所有工作。

The Skeletal System The bones of your skeletal system support the rest of your body. Bones also protect your organs and help you move. Your spine the main support, has twenty-six bones. Your skull protects your brain from getting hurt. Your ribs protect your heart and lungs. Your pelvis helps to protect the organs in your belly.

骨骼系统骨骼系统的骨骼支撑着身体的其他部分。 骨骼也保护你的器官，帮助你移动。 你的脊椎是主要的支撑，有26块骨头。 你的头骨保护你的大脑不受伤害。 你的肋骨保护你的心肺。 骨盆有助于保护腹部的器官。

Long, strong bones support your arms and legs. Your hands, wrists, feet, and ankles have many small bones. Each of the 206 bones in your body has a special job. Did you realize your bones are alive? Bones are made of living cells. This is why bones grow. Bone marrow in the middle of bones 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 sounds from your eardrums to your inner ears.

又长又壮的骨头支撑着你的胳膊和腿。 你的手、手腕、脚和脚踝有很多小骨头。 人体206块骨头中的每一块都有特殊的功能。 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。骨头中间的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!三根小骨头将声音从耳膜传递到内耳。

The Muscular System The muscular system works with the skeletal system so you can move. Your muscles can contract (become shorter and tighter) or relax (become longer and looser.) Your body has three kinds of muscles. Skeletal muscles connect to bones. When you run, smile, or pick up a pencil, your skeletal muscles are working.

肌肉系统肌肉系统与骨骼系统协同工作，你才能活动。 你的肌肉可以收缩(变短变紧)或放松(变长变松)。你的身体有三种肌肉。 骨骼肌与骨骼相连。 当你跑步、微笑或拿起铅笔时，你的骨骼肌正在工作。