2 Bones and Muscles. Ancient Bones

Transcription

1 2 Bones and Muscles Ancient Bones The other day I saw a show about an archaeological site. One of the scientists said that bones talk to us. What do you think this means? Archaeologists have found lots of bones on the site. The bones are more than 300,000 years old. There are teeth and a lot of small pieces of bone. I know bones are hard, but I didn t know that bones could be so old. It is almost impossible to destroy bones. When scientists look at bones, they work like detectives. They put the skeletons together like a jigsaw puzzle. Then they use the bones to find out about ancient man. A small piece of bone can tell them a lot. It can tell them how old a person was, if the person was healthy or sick, and what food they ate. This is why scientists say that bones talk to them. Isn t it incredible that such a small piece of bone can give us such a lot of information? Julie, age 9 18

2 1 Talk about the text Answer the questions. What did the archaeologists find at the site? How old are the bones? What can we find out from a piece of bone? Play with a friend. Point to parts of your body. Name the different bones. 2 Think about the questions Answer the questions. Read the texts. What is under the skin? If we cut the skin, we can see flesh. This is made up of muscles. If we cut even deeper, we can see bones. Could we walk if we didn t have muscles in our legs? What would happen if we didn t have any bones? We need muscles and bones to walk and move around. Bones and muscles have to work together for us to move. 3 Find out about the unit In this unit we are going to learn about: Our skeleton and our bones. Our muscles and how they work. 19

3 Bones and the Skeleton 1. Bones Bones are the hard, rigid parts of our body. Our bones hold our body up. They protect delicate organs like our brain and heart. They also help us move around. Bones have different shapes: 1 Some bones are long, like the femur. The femur is the longest bone in the body and is found in the leg. Some bones are short, like a vertebra. A vertebra is found in the spine. Others are flat, like the skull bones in our head. 2. Cartilage Cartilage is a flexible part of the skeleton. It is not as hard as a bone. We have cartilage in our nose, ears and at the ends of our bones. The skeleton is made up of bones and cartilage. 1 Long bone: femur Flat bone: temporal Short bone: vertebra Types of bones. Bones can be long, short or flat. Ligaments 3. Ligaments Joints are the places where two bones join together. There are two types of joints: fixed joints and moveable joints. Fixed joints are where the bones do not move, for example, in the skull. Moveable joints are where the bones can move in one direction, for example, the knee. These joints are held together by ligaments. 2 2 In knee joints, bones are joined together by ligaments. 20

4 2 4. The skeleton There are more than 200 bones in our body. Here are the names of some bones: 3 The head: the skull and the bones in the face, like the upper jaw. The trunk: the vertebrae, which make up the backbone, and the ribs, which make up the chest or thorax. clavicle skull temporal scapula (shoulder blade) sternum (breast bone) ribs vertebrae pelvis parietal frontal maxilla (upper jaw bone) mandible (lower jaw bone) humerus (funny bone) ulna radius The arms: the humerus, the ulna, the radius and the bones in the hands. The legs: the femur, the tibia, the fibula and the bones in the feet. femur knee tibia carpals, metacarpals and phalanges (finger bones) fibula Vocabulary thorax the bones that surround our heart and lungs 3 The human skeleton tarsals, metatarsals and phalanges (foot and toe bones) Tasks 1. What are bones? Name three different bone shapes. 2. What are joints? Name two different types of joint. 3. Look at picture 3. Name two bones in the head, two in the trunk and two in the limbs. 21

5 ACTIVITIES UNDERSTAND 1. Use the words to complete the sentences. ligaments joints bones The skeleton is made up of and cartilage. Bones are joined together by. hold bones together at the joint. 2. Look and write the letters next to the names of the bones. vertebrae maxilla (upper jaw) carpals (finger bones) A B C Do you and you classmates have X-rays of yourselves? If so, bring them into class. Look at them. What bones can you see? FIGURE IT OUT 3. Answer the questions. Imagine your leg is one long bone. Could you walk? Could you jump or hop? How many joints are there in your index finger? Imagine you have no joints in your fingers. Could you write? APPLY 4. Copy the movements in the pictures. Which joints do you use for each movement? Make a list. A B 22

6 2 LEARNING TO READ 5. Read the text. Answer the questions. What Bones Are Made of The bones in our body are very hard, and they last for a long time. They contain a lot of calcium and other elements. These elements are also found in rocks. Bones are rigid and do not bend or change shape, but they can break. Our bones are living things. They grow and they need food. Our bones use the food to repair themselves. DIBUJO What are our bones like? Choose the best words. Soft and flexible. Hard and rigid. Red and rough. Why are bones living things? Can we heal a broken bone? How can doctors help the process? Which things in the picture are rigid? Summary Bones and the Skeleton The skeleton consists of bones and cartilage. Bones are the hard parts of our body. Cartilage is softer than bones. 23

7 Muscles 1. What are muscles like? Muscles are soft and flexible. They enable us to move our body. They also give shape to our body. Some muscles are joined to bones. Others form part of internal organs like the stomach or the heart. 2. Types of muscles 1 Voluntary muscles in the face. We use the muscles in our face to show feelings. These are voluntary muscles. There are voluntary and involuntary muscles. Voluntary muscles are muscles we can move when we want to. 1 For example, when we want to move our arm, we use the biceps muscle. Involuntary muscles move automatically. We do not make them move. For example, the heart muscle moves automatically. A tendon The arm bends. The biceps gets shorter. 3. Muscles move bones B Muscles get longer and shorter. A muscle gets shorter by pulling on the adjoining bones. Bones and muscles work together to move our body. 2 Muscles are joined to bones by tendons. Bones and muscles make up the musculoskeletal system. 2 The triceps gets shorter. The arm straightens. Movement of the arm. In A, the biceps gets shorter and the arm bends. In B, the triceps gets shorter and the arm straightens. 24

8 2 4. Muscles Every part of our body has muscles. Here are the names of some of them: The masseters are in the face. They move the chin and other parts of the face. We use them to make facial expressions. There are lots of muscles in the trunk, for example, the pectoral, abdominal and dorsal muscles. 3 abdominal masseter deltoid pectoral biceps trapezius dorsal triceps The biceps and triceps are in the arms. sartorius The quadriceps and the gemellus are very strong muscles. They are found in the legs. quadriceps gluteal biceps femoris refractor muscle gastrocnemius rotating muscles (gemellus) 3 Muscles in the human body Tasks 1. What is a muscle? Name five muscles. 2. Is the heart muscle different from the biceps? How is it different? 3. Look at picture 2. Explain how you move your arm. 25

9 ACTIVITIES UNDERSTAND 1. Circle the correct words. Copy the text. The human skeleton consists of muscles / bones. Ligaments / tendons join the muscles to the bones. A muscle gets shorter / longer when the adjoining bone is pulled. 2. What is the difference between voluntary and involuntary muscles? Classify the following muscles. tongue heart quadriceps abdominals voluntary involuntary 3. Match the words to the picture. masseter pectoral biceps abdominal heart gemellus FIGURE IT OUT 4. Answer the questions. What would happen if the heart were a voluntary muscle? What would happen if the abdominal muscles were involuntary? 26

10 2 I CAN DO IT 5. Look at the pictures. Read the texts. Pictures can show how you move your body. 1 arm and hand muscles Lifting and putting down a weight 2 biceps radius 3 triceps ulna First, the muscles in the hand and arm pull on the bones. This closes the hand and holds the weight. Then the biceps gets shorter, and pulls on the radius. The arm bends at the elbow. Finally, the triceps gets shorter, and pulls on the ulna. The arm stretches out and puts the weight down. Look at the pictures. Complete the sentences. Moving a leg backward and forward quadriceps biceps femoris biceps (hamstrings) femoris First, the biceps femoris gets shorter and the leg bends. Then. Finally,. Summary Muscles Muscles are soft, flexible organs. Tendons join our muscles to our bones. Some muscles are voluntary. Others are involuntary. 27

11 Now I Know Check what you know 1. Complete the word map. The musculoskeletal system made up of muscles are joined together by are are hard and rigid can be soft and voluntary moveable Copy and complete the sentences. Use words from the word map. The musculoskeletal system is made up of bones and. Bones are hard and. are places where bones are joined. They can be. Muscles are. 2. Mark the correct words. 1. What kind of organs are bones? Hard. Flexible. 2. The is made up of bones. muscles skeleton 3. What kind of organ is cartilage? Hard. Flexible. 4. Muscles are in the arm. all over the body. 5. Tendons join muscles to other muscles. the bones. 6. When a muscle gets shorter, it pulls pushes on a bone. on a bone. 7. What kind of joint is the knee? Fixed. Moveable. 8. The musculoskeletal system consists of bones and muscles joints. and bones. 28

12 My project 3. Make a model of a backbone. A backbone consists of vertebrae that are joined together. Make a model using paper and rubber bands. 1. Cut a sheet of paper in strips 2cm wide. Use tape to join two strips together. This should give you four long strips. 2. Roll each strip of paper around a pencil. Use tape to join the ends together. You now have a thin tube. Remove the pencil. Make more tubes with the rest of the paper. 3. Pass a rubber band through each tube. Put an open paper clip on each end of the rubber band. This will keep the rubber band in place. What does each small tube represent? What does the line of tubes represent? Citizenship 4. Read the text. Do the activity. Moving around People move around all the time. In this unit you studied the body and how you move using your skeleton and muscles. Many people can t move around easily. They need a wheelchair. Imagine how difficult it is to be in a wheelchair. Draw the route you take from the school entrance to your classroom. Now, imagine you have to follow this route in a wheelchair. Mark all the obstacles you find on your route. 29