Go to page
 
   
 
 
 
 
  Organs work together in organ systems to carry out major life functions. Organ systems also interact with each other.
  Organ Systems
  In dogs, cats, fish, ferns, and you, many cells
work together in tissues. Many tissues work
together in organs. Organs work together in
groups too. An organ system is a group of
organs and tissues that work together to
carry out a life process. For instance, the
mouth, stomach, intestines, and other
organs work together to digest food.
  Bones Form a System
  Each of your bones is an organ. Together,
about 200 bones make up the skeletal
system. This organ system has several
important jobs. It provides the body with
a strong support system. Imagine what
life would be like if you did not have
bones to help you stand or sit up. You
would move like wiggling worms!
Another job of the skeletal system is
to protect internal organs. The skull is
made of several bones that work
together to protect the brain. The rib
cage protects your lungs and heart.
Bones have other jobs too.
  Muscles Work as a System
 
 
  Bones Work
Together
  This is a cut-away
view of where the
bone in your leg
meets the bone in
your hip.
 
  Muscles are organs that work together to move your body. You have about 640
muscles that you control. When you run or dance, your brain tells dozens of these
muscles how to work together. In other cases, muscles work by themselves
without your thinking. Have you ever shivered in cold weather? Shivering can help
you survive the cold. When you shiver, many muscles are working together to warm
the body. You do not have to think about shivering for it to happen.