What Ava Marsh Knows About The Human Body

    The human body is a complicated and intricate thing.  There are many systems that interact with each other such as the nervous system, the digestive system, the respiration system, the reproductive system, and the excretory system.  Each of these systems work together to keep our body alive.
     The foundation of our body is bones.  Without them, we would be jello.  There are a lot of bones in our body.  Bones provide structure, and also protect certain organs.  On top of bones is muscle.  As shown in the diagram, there are different names for different muscles.  Muscles help our body move.  On top of muscle is skin.  Skin protects the body from pathogens and the outside environment.
    The brain is the control center of the body.  It sends and receives signals that control reactions, functions, and thoughts.  The brain also stores memories in these signals.  It controls all the organs, such as the heart, which pumps oxygenated blood through the body, the stomach and intestines which digest food, and the eyes which allow us to see.

     These organs are made up of things called cells.  Cells are the basic units of life, as shown in the picture.   There are many different types of cells in the human body that each serve a specific function, such as skin cells, brain cells, and liver cells.  Every cell in our body contains a nucleus that holds DNA.  DNA is a genetic code that carries instructions for basic life.  The DNA codes for protein synthesis. Proteins basically make up everything.
    Cells are made up of atoms grouped together to form different compounds and substances.  Over 75% of our body is H₂O.
   The cells in our bodies need certain things to survive and function properly.  That is why we need to eat, breath, and sleep.  Sleeping a very important process in which the cells in our body need to recharge.  Most of healing, growing, and regeneration happens when people sleep.  That is why it is important for adults to get eight hours per day.  Teenagers need even more sleep because they are growing and developing.  Most people fail at getting adequate sleep.