Читать книгу The House We Live In; or, The Making of the Body онлайн

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Percy: The spaces between the timbers were filled with bricks, so there was a solid wall.

Mother: Well, it is that way in the body-house. The bones are all covered over and filled in between with muscles. It is these which make the cheeks so plump, and give the whole body its round, pleasing form. It is the muscles which move the bones.

Amy: But what is a muscle?

Mother: You have seen lean meat, have you not? That is muscle. When boiled it seems to be made up of little bundles of tiny threads of fibers, each wrapped in its own thin blanket. Here is a picture of a muscle. These small threads are not twisted together, but are laid side by side. It takes one thousand seven hundred of them to make a muscle an inch thick in children, but in grown people it takes only five hundred.

Helen: Are the muscles fastened to the bones, mother?

“Muscles of the arm, with their tapering tendons at the wrist.”

Mother: Yes; many muscles are joined to the bones by strong cords, called tendons. The picture shows the muscles of the arm, with their tapering tendons at the wrist. You see our muscles end in these little ropes, or cords, to save room. What a large wrist we would have if the muscles were as large there as in the arm! Now grasp your right arm and open and shut the fingers of your right hand. What do you feel?