Life Cycle - Human Biology (KB)
Lab 

   
OBJECTIVES:
  • Comparing different models of skeletons.
  • Counting bones in the human body. 
VOCABULARY:
  • backbone
  • finger
  • foot 
  • jaw
  • leg
  • pelvis
  • skull
  • tail bone
  • wrist
MATERIALS:

Students discover how many bones are in a human skeleton.

 

BACKGROUND:

The common name for the combination of all the bones in the body is called the skeleton.  The skeleton has several important functions: 

a) a framework that provides a shape for the body; 
b) a solid anchor for attachment of muscles; 
c) production of blood; and 
d) protection of the brain, spinal cord and other vital organs.

Living bone tissue varies in hardness.  The outside of most bones are very hard.  Minerals give bone tissue its hardness.  Inside the bones is a soft material called marrow, which is responsible for the production of blood cells.   Cartilage is generally found at the ends of bones that move against one another.  Cartilage is a smooth, flexible material that is tissue.  Ligaments  are tissues that may be found at the ends of bones if the bones are still held together.  There are 206 bones in an adult  skeletal system.   A child's skeletal system has up to 275 bones.  Some of  the bones will fuse together as the child grows. 

Bones articulate at joints and are held together there and allowed to move with the help of ligaments.  Bones and muscles are attached to each other by means of tendons.  This combination of muscle and bone provides an extraordinarily effective means of movement.  

PROCEDURE:
  1. Give groups of students a skeleton.   Ask students to compare the  skeletal model with their own body.  They can  compare by counting the bones of each of the models and see if they have the same number.  
       
  2. Give students either the Human Body Placemat or the worksheet of a skeleton, to count how many bones there really are. As they will find out, most skeletal models are incorrect in one way or another.  Note that some books have varying numbers, because different numbers of bones appear at different growth stages.  Younger children have more bones because some of them will fuse in later life.

  3. Use the Box of Bones puzzle to show students where the major pieces go together.  After you show them the electronic version provide them with the real Box of Bones and challenge them to put it together especially by looking at the other skeletons to help them along. 

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