Also, because this is homework, I don't know if you are familiar with the concept of inheritance and given that we don't have the full assignment - is it possible that you are asked to have some of your classes inherit from some of the other? I admit that human body is not best example to implement inheritance, but who knows...
If you can't explain it to a six year old, you don't understand it yourself, Albert Einstein
How to Ask Questions The Smart Way: link and another link
Create MCV example
Debug small programs
How to Ask Questions The Smart Way: link and another link
Create MCV example
Debug small programs