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The skeleton: bones and joints

Around age 7 · Usually taught in ⁨Year 3⁩ · Free

Aprende

  1. Your body has a skeleton. The skeleton is all your bones together. Bones are hard, but they are alive: they grow and, if they break, they heal again. They are not made of stone.

    with restbroken bonehealed bone
    A broken bone heals by itself, with rest

  2. An adult has 206 bones. A baby has more, because some bones join together as we grow. The longest bone in the body is the femur, the thigh bone.

    ribshumeruspelvisfemurkneecaptibiaskullbackbone
    The main bones

  3. The skeleton does three jobs. It supports the body and gives it its shape. It protects what is inside: the skull looks after the brain, and the ribs look after the heart and the lungs. And, with the muscles, it lets us move.

    skeletonsupportsthe bodyprotectsorganslets usmove
    The three jobs of the skeleton

  4. The backbone is not a single bone. It is made of lots of small bones, one on top of another. That is why we can bend our backs. To have strong bones, eat a varied diet and move every day.

    Bones do not bend. Joints bend: they are the places where two bones meet. The knee, the elbow and the shoulder move a lot. The joints in the backbone move a little. Those in the skull do not move: they are fixed.

    jointsmove a lotmove alittledo not move
    Three types of joints

Worked examples

Ejemplo 1

Gus puts his hand on his chest and feels some hard bones, in a row. Which bones are they and what do they protect?

  1. The bones in the chest are the ribs.
  2. They form a cage around what is inside.
  3. They protect the heart and the lungs.

They are the ribs, and they protect the heart and the lungs.

¡Ojo! Many children think that the chest is soft and has no bones.

Common mistake

Ejemplo 2

Julie broke a bone in her arm. After a few weeks, the bone is fine. How is that possible?

with restbroken bonehealed bone
  1. A bone is alive.
  2. If it breaks, the bone itself makes new bone and joins the pieces together.
  3. That is why the doctor keeps it still with a plaster cast: the bone needs time to heal.

The bone healed because bones are alive.

¡Ojo! Many children think that bones are made of stone and cannot mend themselves.

Common mistake

Ejemplo 3

Tony bends his knee to get onto his bike. Is the knee a bone or a joint?

femurtibia
  1. Bones are hard and do not bend.
  2. Two bones meet at the knee: the femur and the tibia.
  3. A place where two bones meet is a joint. The knee is a joint and it moves a lot.

The knee is a joint, not a bone.

¡Ojo! Many children think that it is the bone that bends.

Common mistake

Un reto para pensar

Touch your head, your ribs and your knees with your hands, and feel which part is hard. Bend your elbow and your knee. Draw a skeleton and mark three joints that bend.

Practica

Rondas de 10 preguntas. Elige el nivel:

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